







7 spheres on a hexagonal tray 
20190114 

From herm: what is the length of each side of a hexagonal tray, with the height of each side 0.75 inch, to hold seven spheres, each with a diameter of 3.00 inches? The spheres are placed such that each side of the hexagon is touched by one sphere at its midpoint (and the seventh sphere is place in the center of the "ring" of the other six spheres. Answered by Harley Weston. 





The base for a circular pool 
20180610 

From Adam: How many sheet of 4ft by 8ft foam would I need to lay under a pool 15dt in diameter Answered by Penny Nom. 





Base 6 to base 4 
20180325 

From Malik: Hi Sir..!
I just want to know the proper example with a brief explanation of conversion of base 6 into base 4.
kindly reply me as soon as possible..
Thank you Answered by Penny Nom. 





Baseball Cards 
20170420 

From Raquel: A minor league baseball team gave away baseball cards to each person entering the stadium. One group receives 28 baseball cards. A second group received 68 baseball card. If each person entering the stadium receive the same number of cards, what was the greatest possible number of baseball cards that each person could have received? Answered by Penny Nom. 





Forming a cone from a circle 
20170415 

From Tasha: A sector of a circle subtends an angle of 216 degrees at the centre, If this sector is used to form a cone of vertical height ,8cm, calculate the base radius of the cone Answered by Penny Nom. 





A block base for a plywood rectangle 
20170218 

From Joe: How many cinder blocks 16x8 would i need to build a solid base for a plywood base 54inches wide and 30 inches deep Thank you Answered by Penny Nom. 





Addition and subtraction base 5 
20170129 

From BABAWALE: Simplify 342five +132five223five Answered by Penny Nom. 





4444 base five 
20161111 

From John: If 4444 is a number in Base5, is 624 its value? Answered by Penny Nom. 





Subtraction of two numbers in different bases 
20161007 

From Wica: Hello,
So happy I found this site. I am having problems with bases. My question is :
Please perform the subtraction between two number over different bases :
A. (5874)base 12  (216)base 9
B. (216)base 9  (5874)base 12 Answered by Penny Nom. 





A square based box and a cylinder 
20160326 

From rajpal: i m trying to calculate an area required to hold 4.4 mln cubic metres of volume.
I used square and I get below result
A box shape that has dimensions 1500 meters (1.5km) by 1500 meters (1.5km) by 2 meters depth has a volume of:
= 4,500,000 cubic meters (4.5 mln cubic meters)
but when I use a cylinder shape, i get below result
A cylindrical shape that has a radius of 850 meters and a depth of 2 meters has a volume of:
= 4,539,600 cubic meters (4.54 mln cubic meters approx)
why is it that the cylinder, though of same depth holds more volume than a square?
kindly clarify. Answered by Penny Nom. 





A problem in base x 
20160325 

From Malith: determine the value of base x of (211)x = (152)8
please mentioned the steps
Thank you Answered by Penny Nom. 





Division base 5 
20160201 

From Jenalee: I am having problems with a dividing bases question. I reviewed two that I could find in the database and tried the question as shown but I am still getting the wrong answer.
My question is 32\24043 to the base of 5 for both. Answered by Penny Nom. 





Subtraction in a base larger than ten 
20160131 

From Jenalee: Hello,
So happy I found this site. I am having problems with bases. My question is 97B9  6A3A base 16 for both.
Please help. Answered by Penny Nom. 





Subtraction in base 8 
20151021 

From Adi: Hi!
Can you help me with a nagging problem, I searched a lot over the web and couldn't find it.
I saw this site I gave it a try and I found it to my liking.
I am confused how to subtract bases from other bases:
567 (in base 8)
 456 (in base 8)
______________
?????????
How do you do this? I do know how to carry and subtract with different bases. Can
you please help me?
Thanks,
Adi Answered by Penny Nom. 





Subtraction base 5 
20150829 

From nakita: can u explain the quinary subtraction ...
(3000) (2342) all the numbers are in quinary number system Answered by Penny Nom. 





Excavating a basement 
20150412 

From Randy: The cost of excavation is $4.50/ cu yd. Find the cost of excavating a basement 87 ft long, 42 ft wide, and 8 ft deep. Answered by Penny Nom. 





Integers in different bases 
20150305 

From Michael: Let k be a positive integer so that 28 (subscript)k = 132 (subscript)5 Answered by Penny Nom. 





211basex=152base8 
20141215 

From Humaira: 211basex=152base8 Answered by Penny Nom. 





A truncated, squarebased pyramid 
20141123 

From Hannah: A designer vase has the shape of a truncated, squarebased pyramid. The base of the vase is a square with a side length of 15 cm. The area of the square opening is 70.56 cm2. Each of the four sides is a trapezium with slant sides 9 cm long. Find (to the nearest square centimetre) the total surface
area of the vase. Answered by Penny Nom. 





logbase4 (sin x) = 0.5 
20141026 

From Susan: Solve for x: logbase4 (sin x) = 0.5 Answered by Penny Nom. 





A truncated squarebased pyramid 
20141022 

From Beth: How do you find the height of the original squarebased pyramid when given the sides (12cm) of the base and height (6cm) of the truncated pyramid, as well as the sides (3cm) of the base of the chopped off top (chopped off parallel to the base)? Answered by Penny Nom. 





Division in base 3 
20140930 

From Nnubia: 1021 in base 3 divided by 2 in base 3 Answered by Penny Nom. 





Base 6 
20140910 

From Amanda: using base 6, what is the next number after 25? 35? 55? and 455?
I need to be able to show the base 6 material. Answered by Penny Nom. 





35 base 6 
20140910 

From Amanda: Sorry I am having trouble understanding base,
35 in base 6 means 3 10's and 5 ones, which is the same ____ in base 10? Answered by Penny Nom. 





211(base x)=152(base 8) 
20140909 

From Vaidehi: Find the base value (i.e. x):
211(base x)=152(base 8) Answered by Penny Nom. 





Multiplication in base five 
20140807 

From Alise: Hi Maths Central!
I was wondering if you could help me with multiplying in base 5. I have read a question previously answered by you in regards to this but got fairly confused by it and was hoping you could help me with my question.
My question is: Multiply 1422 base 5 by 21 base 5 keeping these numbers and answer in base 5.
Would you also be able to explain how to get to the answer?
Thanks! Answered by Penny Nom. 





How can eight eights be 1000? 
20140620 

From Aamir: The digit 8 if we add it 8 time in it the answer should be equal to 1000.it may possible.i.e.,
8+8+8+8+8+8+8+8=1000 Answered by Penny Nom. 





Forming a cylinder from a square 
20140608 

From kalyani: the curved surface of a cylinder is a square of diagonal 2*square root of 2. What is the area of the base of the cylinder? Answered by Penny Nom. 





6 inches of dirt in a baseball field 
20140601 

From Mary: The baseball field is 20,000 Square feet, 6 inched deep
I need to know how many cubic yards of dirt this will generate. Answered by Penny Nom. 





Converting to base 5 
20140410 

From Usama: Convert the numbers used in the following expressions into those of basefive and solve :
21+34108+62
Convert the result so obtained into decimal system and thus check your answer? Answered by Penny Nom. 





The diameter of the base of a cone 
20140223 

From elwin: i have a sector of a circle that has 120 degree and 6 cm length. What will be the diameter of the base of the cone.
and what is the diameter of the angle is changed to 180. Answered by Harley Weston. 





Counting in base five using words not digits 
20140125 

From Randy: We all know how to count (in the base 10/decimal system) using words not numbers. For example: one, two, three, four, five, six, seven, eight, etc. However, in base 5 (for example) how would you count (in words). For sure  in base 5 the number 1 could be "one", the number 2 could be "two". However there seems to be no words to describe base 5 numbers beyond 0,1,2,3 and 4 (and perhaps 10). In base 5 the number 10 is not ten. Rather it is "five". In base 5 what word(s) describe numbers larger than 10? What words are used for 11, 12, 13, 14, 20, 21, 22, 23, 24, 30, 44,...etc. Also, consider a man and woman were married in the Gregorian year 1964. If they had an anniversary tomorrow  how long would you say they've been married in base 5 speak? In numbers their Golden Anniversary would note 200 years of marriage in base 5. How would you articulate their years together in base 5? I don't recall seeing verbiage to represent numbers in any system other than the decimal/base 10 system. Do such things exist for other systems? Answered by Harley Weston. 





Base 5 arithmetic 
20131127 

From samuel: Good day sir, please i don't understand when you say 4x4=13 in base five? In fact, am always having difficulties in addition, subtraction, division and multiplication of number in the same base other than base ten. Please can you give me one example each with details explainations? Answered by Penny Nom. 





Base 5 arithmetic 
20131012 

From Obassy: (4 2 4 3)(1 3 x 4)=( Y 3 4 4),find the value of x and y in the subtraction above carried in base five? Answered by Penny Nom. 





Base 5 
20130930 

From Zakir: Sir I wanna know something about base 5 number system
Why we use it and who use this ? and what is the purpose of it Answered by Robert Dawson. 





How can I teach how to change bases? 
20130220 

From Tammy: How can I teach how to change bases? For example 80 base 10 changed to base 3.
Thank you! Answered by Harley Weston. 





Multiplication in base two 
20130201 

From Michael: multiply in the indicated base
110two*11two Answered by Penny Nom. 





The multiplication table for the different bases 
20130201 

From sylvia: I am having a difficult time trying to figure out how to fill in the multiplication table for the different bases. i don't know how to get the numbers. Answered by Penny Nom. 





The hypotenuse 
20120906 

From Jeevan: how can i find the height and base of a right angle triangle if i have the hypotenuse only ? Answered by Penny Nom. 





Expanded exponential form? 
20120612 

From Ramon: express the numbers 990 614 000 005 in expanded exponential form. Answered by Harley Weston. 





Division in base eleven 
20120527 

From Zoe: How do you divide numbers that are in base 11?
For example;
9A7A6A divided by A Answered by Penny Nom. 





How to find the base length of a isosceles triangle if only the sides are given? 
20120425 

From aqilah: how to find the base length of a isosceles triangle if only the sides are given? Answered by Chris Fisher. 





The number of digits in a number base m 
20111222 

From Jash: Assume there is a number system of base m.
The one property of this system is: If 2 numbers written in this system, which have 'a' and 'b' as the number of digits are multiplied, then the product of the 2 numbers will have a number of digits which is a function f(a,b).
In other words, as long as the number of digits of the 2 numbers are constant, the number of digits of their product is a constant.
Find m. Answered by Robert Dawson. 





Converting from base 4 to base 10 
20111129 

From anjg: How to convert base 4 number 2^11 to base 10 number? Answered by Penny Nom. 





Expanded form 
20111012 

From Chris: Write this number in expanded form
4 326 180 501
Thanks!!! Answered by Penny Nom. 





Converting base 3 to 5 
20110228 

From Harry: Hey Math Central, I came across your website and im in need of help on my maths c assignment. I have to convert base 3 to 5 without converting back to ten. I heard that you can use patterns in 3 and 5 to make an equation but im not sure how to and i also heard you can use logarithms but i dont know how to use those so im kinda stumped. Answered by Robert Dawson. 





A player runs from second base to third base 
20110130 

From Marie: A baseball diamond is a square with side 90 feet in length. A player runs from second base to third base at a rate of 18 ft/sec. At what rate is the area of the trapezoidal region, formed by line segments A, B, C, and D changing when D is 22.5
Distance A is the players distance from first base when running from 2nd to third. Distance D is his distance from 3rd base. Distance C is the distance from 3rd to 3rd to Home. Distance B is the distance from Home to First.
I have found dA/dt in a previous problem. Answered by Penny Nom. 





How far must the pitcher travel to get to the ball? 
20101104 

From ken: A baseball player bunts a ball down the first base line. It rolls 35ft at an angle of 26 degrees with the first base path. The pitchers mound is 60.5 ft from the plate. How far must he travel to get to the ball. Answered by Penny Nom. 





The base of an isosceles triangle 
20101024 

From Brian: how can I find the base of an isosceles triangle from the height and the perimeter? Answered by Penny Nom. 





An 18ft round pool 
20100719 

From christine: will an 18ft round pool fit on a 12x16 ft rectangular cement slab? Answered by Tyler Wood. 





The number of gallons of water in a basement 
20100523 

From George: A basement with dimensions 68 ft long by 42 ft wide by 10 ft deep is flooded to the ceiling calculate the number of gallons of water in the basement. 70 Answered by Penny Nom. 





Divisibility by 3 
20100523 

From Cathleen: To math central. I have to do a maths extension question that I don't understand. At first I thought I did.
It is about the dividing by three. In one part of the question, it asks me to show that the rule of division by three does not work for 23142 with a little 5 down the bottom.
What doe base 5 mean? We first thought that the little 5 down the bottom meant multiplying y the power of five.
Can you please tell me what it means so I can finish this question? Answered by Penny Nom. 





The base area of rectangular prism 
20100305 

From Desiree: How do you find the base area of rectangular prism that has 4 cm by 4cm by 6cm ? Answered by Penny Nom. 





Triangles on a base of 2.4 meters 
20091226 

From Allan: Please,How do I calculate the height of a triangle when I only know the width of the base line,It is 2.4 mtrs. Thankyou very much. Answered by Penny Nom. 





Bases larger than ten 
20091214 

From Nick: For numbers in bases larger than ten, what are the digits by mathematicians' conventions?
I assume the first 10 are always 09. I know two computer science conventions (for hexadecimal (AF caseinsensitively) and for base 85 (casesensitivity plus 23 other characters)) and as a school student I learned that base 12 uses either T and E (which confused me when I thought they stood for Eleven and Twelve) or A and B, the latter as capitals only. Clearly, these conventions are in conflict.
I saw your reply in http://mathcentral.uregina.ca/QQ/database/QQ.09.99/magin1.html as accessed a few minutes ago but hope that in the 10 years since then mathematicians have arrived at a convention. Have they?
Thank you.

Nick Answered by Claude Tardif. 





A number base that's not a positive integer 
20091211 

From Nick: Is it possible for a number to have a base that's not a positive integer?
Base 1 gives a result that's meaningless but possible. I have no concept of a base 0, a negative base, or a fractional base, never mind any other base. I think there isn't any base that's not a positive integer, but, knowing that math keeps jumping ahead and sometimes has inventions before anyone knows how to exploit them, I think I'd better ask.
Thank you.
Nick Answered by Robert Dawson and Claude Tardif. 





A baseball diamond 
20091118 

From maelee: the official distance between home plate and second base in baseball diamond is 120ft. Find the area of the official ball diamond & the distance between the bases. Answered by Robert Dawson, Chris Fisher and Penny Nom. 





A drawing of a baseball diamond 
20091109 

From Beth: My husband has a drawn diagram on a piece of paper of a baseball diamond. He knows that on the paper 1 1/16" (1.6875") = 90 actual feet. How do we calculate how many feet 5 7/8" on the paper would be? Answered by Penny Nom. 





Subtraction base 5 
20090809 

From Nikki: can you help me how to do subtraction in base 5 notation. example is 3434  51?
how do you do this in base 5?
can you please explain how you do this & the answer as i have no idea.
Thank you kindly
Nikki Answered by Harley Weston. 





A base 7 number and a base 9 number 
20090709 

From koteawarao: Find a base 7 threedigit number which has its digits reversed when expressed in
base 9.
ans: (281) base 7 and (182) base 9 Answered by Harley Weston. 





How do you convert 1248 to base 6? 
20090502 

From Tamara: How do you convert 1248 to base 6? Answered by Penny Nom. 





Adding in base six 
20090329 

From Lucy: If you are working in base 6,
what do you have to add to 4(base 6) to get 10(base 6)???? Answered by Penny Nom. 





The base of a triangle 
20090325 

From yinna: how do I find the base of a triangle who's height is 2 times the base and the area is 9? Answered by Penny Nom. 





The base and height of an isosceles triangle 
20090323 

From Chris: How do you find the base and height of an isosceles triangle that has 2cm legs? Answered by Harley Weston. 





Multiplying in different bases 
20090225 

From Susan: 11 base 2 X 22 base 3 + 33 base 4 = _________ base 5 Answered by Robert Dawson. 





In what base is 3x3= 10? 
20090214 

From David: In what base is 3x3= 10, 3x3=11, 3x3 = 12? is there a fast way to see this or do I have to create multiplication tables until I find the right one? Answered by Penny Nom. 





Division in different bases 
20081202 

From MICHELLE: DIVIDE 538 BY 14 IN BASE 2, 3, 4 & 5 Answered by Penny. 





A log base 2 problem 
20081126 

From dave: solve for x
(log base 2 of x)  (log base 2 of (x2)) = 3 Answered by Penny Nom. 





The height, base and perimeter of a triangle 
20081117 

From Zack: How would i calculate the height of a triangle if the base is 10cm and the area is 50cm²?
If possible how would i calculate the length around the the triangle. Answered by Penny Nom. 





Bags of pennies 
20081011 

From paul: jenny divided 15 pennies among 4 money bags.she could then pay any amount from 1p to 15p just by giving bags.how many pennies did jenny put in each bag? Answered by Penny Nom and Victoria West. 





The height and base of a triangle 
20080912 

From Bailey: The length of the base of a triangle is 1cm less than 5 times the height of the triangle. The area of the triangle is 21 square cm. What is the the height of the triangle and the length of the base of the triangle? Answered by Stephen La Rocque. 





Aboriginal number groupings 
20080904 

From Barbara: Our current place value system is based on the notion of 10s. Did Aborginal people use a similar system or did they group numbers differently? Answered by Harley Weston. 





Four weights 
20080825 

From Darla: A balance had known weights of 1/2 lb, 1/4 lb, 1/8 lb, and 1 oz. Edna's object weighted 2 oz. more than Paul's. Each used 3 known weights to weight his or her object. which know weights did each use? Answered by Penny Nom. 





The base of a triangle 
20080810 

From Mark: What is the formula I need to use to find the base of a triangle sail that is 16 feet high and has an area of 64 square feet. Answered by Stephen La Rocque and Penny Nom. 





Angles in a regular tetrahedron 
20080807 

From Carla: Hi guys,
A regular tetrahedron has all its edges 8cm in length.
Find the angles which an edge makes with the base.
Thanks.
Carla Answered by Penny Nom. 





How do you change bases? 
20080617 

From Peter: How do you change bases eg. 121 from base 3 to base 5? Answered by Penny Nom. 





The path of a baseball 
20080604 

From Tom: How high would a batter have to hit a ball to clear the stadium roof in right field
if the distance to the right field fence is 320 feet from home plate? Is this solvable? Answered by Janice Cotcher. 





Base 5 arithmetic 
20080306 

From Jana: Hello, my name is Jana, i have asked a question here previously about how to count in base5. I am happy now because i can convert any number now and it is very easy for me. The only thing i am having trouble with is understanding how to do a maths sum or times base5 numbers. it is just a bit hard for me. So do you think you could explain how to do a sum in base5 and how to do a multiplication sum. Please help...Thankyou Jana!! Answered by Harley Weston. 





Convert from base 6 to base 12 
20080302 

From Jade: I am trying to convert 13405 base 6 to a base 12 number. I am not allowed to go into a base 10 number. How will can I base 12 without doing anything with base 10? Thank you kindly. Answered by Stephen La Rocque and Penny Nom. 





Counting in base 5 
20080224 

From Jana: my name is Jana, i really need help with a maths question at school. Im confused about how to count up from120 in a base5 format! I'm in year 5 and i really don't get all the complicated stuff. Answered by Stephen La Rocque. 





Multiplying numbers in bases other than 10 
20080108 

From Imaiya: In class we've been learning about numbers with a base other than ten. For example, base 7, base 5,
and base 6. What's really stumping me is how to multiply these numbers, when they aren't a base of 10.
I've had it explained to me once, but don't seem to understand it. Here are the equations, and I've listed the first few numbers for that particular base.
Base 5: 0,1,2,3,4,10,11,12,13,14,20 etc... The Equation: 34 x 42
Base 9: 1,2,3,4,5,6,7,8,10,11,12,13,14, etc... The Equation: 56 x 78
If you could explain to me how to multiply numbers with any type of base, I'd really appreaciate it. Also
if you could show me how to do one of the questions that I listed, that would really help me =) Thanks so much,
and once again, thank you for your great site! Answered by Stephen La Rocque. 





Representing different bases 
20071205 

From Sudhir: What does a number subscripted to another one denote? (I know that a number superscripted to another denotes the power, but the subscript number is something I have never seen before.) Answered by Stephen La Rocque. 





The base and height of a triangle triangle 
20071031 

From mike: How do you find the length of the base or the height of a triangle if the area is 30 square feet? Answered by Penny Nom. 





Converting bases 
20071024 

From Johanna: Is there an easy way to convert from base to base. For example, base 5 to base 9 or base 2 to base 4 etc Answered by Stephen La Rocque and Penny Nom. 





Paying with silver  Part 2 
20071017 

From Shanna: The paying with silver problem. I understand how to do the problem, but could you please explain how you would use base 2 arithmetic to solve it. Answered by Penny Nom. 





Base 10 to base 5 
20071009 

From Angela: I've been searching online for the past week and I cannot find an Algorithm to convert from base 10 to base 5. Can anyone give me a stepbystep instruction on how to do this? Answered by Stephen La Rocque. 





Log base 2 of log base 2 of x 
20070627 

From alex: y = log base 2 of lag base 2 of x
The slope of the tangent to the given curve at its xintercept is..? Answered by Harley Weston. 





Base seven 
20070519 

From Dan: A number X is converted to base 7 and becomes a four digit number. Its leftmost digit is removed and written again as the rightmost digit. The number thus obtained is twice X. Find the decimal representations of all such numbers X. Answered by Penny Nom. 





In what base does 25+25=51? 
20070403 

From Jenna: In what base does 25+25=51? Answered by Stephen La Rocque and Penny Nom. 





Finding the vertical height of a roof 
20070305 

From Zainab: The question is: If the vertical height if a triangle is half the width of the base and the slant length is 6 metres, find the exact vertical height of this part of the roof. I'm actually confused about finding out the height of an equilateral triangle if you're only given the length or slant height. Please help! O.o Answered by Stephen La Rocque. 





A 3digit number in base 7 has its digits reversed when expressed in base 9. 
20070128 

From Ashley: A 3digit number in base 7 has its digits reversed when expressed in base 9. Find this number. Answered by Penny Nom. 





Base 5 
20061211 

From Shelley: how do you convert decimal numbers to a given base for example 2,875 to base five? Answered by Stephen La Rocque. 





A problem involving logs 
20061126 

From Beth: any help would be appreciated on how to solve without using the change of base formula for logarithms in the solution and check of the solution!!!
log256 (x) + log16 (x) + log4 (x) + log 2 (x) = 7/4 Answered by Stephen La Rocque and Penny Nom. 





Arithmetic with base 2 
20061126 

From Yuva: can we do arithmetic ,base 2. If yes, how and if not, why. Answered by Stephen La Rocque. 





A cone with an oval as base 
20060301 

From Richard: I am trying to find the volume of a cone that is not round but oval. Answered by Penn Nom. 





how can i find the height of a triangle if i have the base and the hypotenuse 
20060127 

From Kelsey: how can i find the height of a triangle if i have the base and the hypotenuse Answered by Penny Nom. 





Converting from base ten to base five 
20050921 

From Julie: My sister is home schooled and we are trying to convert from base 10 to base 5. We are trying to teach and we have never had this in school. If we could have some examples of some problems and how to do them we would appreciate this. Answered by Penny Nom. 





cos x * cos 2x * cos 4x * cos 8x 
20050829 

From Leandro:
A = cos x * cos 2x * cos 4x * cos 8x
What's the value of log A at base 2?
Answered by Chris Fisher and Penny Nom. 





The base of a triangle 
20040525 

From Ralph: With a 30 degree angle at the top of a triangle and a height of 15 what is the base? Answered by Penny Nom. 





Related rates and baseball 
20040426 

From Bethany: A baseball diamond is the shape of a square with sides 90 feet long. A player running from second to third base at a speed of 28 feet/ second is 30 feet from second base. At what rate is the player's distance from home plate changing? Answered by Penny Nom. 





Baseball games 
20040314 

From Fabian: Let's say I have 12 different Baseball games. There is one of only 2 possible outcomes for each of the 12 games. How would I fugure out how many combinations there are for the 12 games and for 11,10, and so fourth.
Answered by Penny Nom. 





Arithmetic in bases other than 10 
20031022 

From Kim: how do you add, subtract, multiply and devide in base 3, base 5, etc? Answered by Penny Nom. 





1 + 1 = 10 
20030917 

From David: could you please explain to me how 1+1=10 thanks Answered by Penny Nom. 





Converting from base 10 to base 5 
20030910 

From Susy:
My son, who is 9 in grade 5 has been asked to convert base 10 numerals into base 5. His first question of: 24(10) he has calculated to be 4x5 + 4x1 = 44 (5) The next question however is the tricky one.Ý We know the answer is supposed to be 100 but we find it difficult to get this in the way he understands it. 25 (10) = _________________ 100 (5) Can you help us figure out how we reach the answer. Answered by Claude Tardif and Penny Nom. 





Converting to base 10 
20030828 

From Karen: My son is in 5th grade.Ý He is learning how to convert numbers from base 2 to base 10, and base 5 to base 10.Ý Can you explain it to me in the simplest terms? Answered by Penny Nom. 





How many hits? 
20030406 

From Jack:
My name is Jack. I'm a uncle. Student is in the 5th grade email is above. If a baseball player at sping training had a good season with the following: one seventh of his hits were doubles. 12.5% of his hits were home runs. But didn't have any triples. How many hits did he have? Can you give me an explanation of you solved the problem. Answered by Penny Nom. 





Numbers in base 5 
20030216 

From Lori: I'm trying to help my 6th grader with converting numbers like 82 to base 5 and 182 to base 12. We saw your examples on 613, but still are confused. Answered by Penny Nom. 





A rectangular prism 
20030109 

From Julie: How many faces on a rectangular prism and how many bases? Can the base also be a face and can a face also be a base? Answered by Diane Hanson. 





Jimmy's hits 
20021027 

From Patty: One seventh of Jimmy's hits were doubles 12.5% of his hits were homeruns Jimmy had 82 singles He did not have any triples
How many hits did Jimmy have? (Be sure to include the equation that represents the number of hits) Answered by Penny Nom. 





Baseball, basketball and football 
20021008 

From Debbie: The school newspaper is interviewing 6th grade students to see what sports they follow regularly on TV. Of the 70 students interviewed; 40 enjoyed basketball; 40 enjoyed baseball; 40 enjoyed football; 20 enjoyed basketball and football; 22 enjoyed baseball and basketball; 27 enjoyed football and baseball; and 12 enjoyed all three sports. How many students out of the 70 interviewed didn't follow any one of the three sports? Answered by Leeanne Boehm, Penny Nom and Walter Whiteley. 





Base 5 numbers 
20020913 

From Vera: ? how do you change a base 10 number to base 5 Answered by Penny Nom. 





Baseball and sit ups 
20020131 

From A student: A baseball team won 8 more games than it lost. If it played 56 games, how many games did it win? On the first day of practice, Paul did 3 sit ups. On the second day he did 5, and on the the third day he did 8, and on the fourth day he did 12. If this pattern continued, how many situps did ihe do on the sixth day of practice? Answered by Penny Nom. 





Papy's Computer 
20020111 

From MaryAnne: My secondgrade son brought home a fun math worksheet which involved calculating sums using "Papy's Computer." I had never heard of this before and found it to be quite interesting. Each digit in a decimal number is represented by a 2x2 grid. Each grid square corresponds to one of the numbers 1,2,4, or 8. Answered by Harley Weston. 





The best of 7 
20010908 

From Michelle: Professional basketball, hockey, and baseball championships are decided on the best 4 out of 7 games. The first team to win four games wins the championship. In how many possible ways could the team win the championship series after winning the first game?
Example:
Game 1 2 3 4 5 6 7
Result W L L W W W
Answered by Leeanne Boehm. 





Arithmetic in base 5 
20000920 

From Lesley Emerson: my daughter is 9 and has been aske to solve the following in base 5 3+2 4+10 . . . Answered by Penny Nom. 





Two calculus problems 
20000501 

From Kaushal Shah: How Do WE Integrate the following Functions,  Integral xtanx dx
 How was natural base "e" discovered and why e=2.7.......
Answered by Claude Tardif. 





Paying with silver 
20000426 

From Luther Jackson: A silver prospector is unable to pay his March rent in advance. He owned a bar of pure silver, 31 inches long, so he made the following arrangement with his landlady. He would cut the bar, he said into smaller pieces. On the first day of March he would give her and inch of the bar, and on each succeeding day he would add another inch to her amount of silver. She would keep this silver as security. At the end of the month, when the prospector expected to be able to pay his rent in full, she would return the pieces to him. . . . Answered by Claude Tardif and Penny Nom. 





Play ball 
20000203 

From Jessie: Here's a calc question that is probably a lot easier than I am making it. If you have a legendary "baseball problem" for the related rates section of Calc I, and you are given that the runner is running from 2nd to 3rd base at a given rate, and the umpire is standing at home plate, and you are given the distance between the bases on the field, how do you find the rate of change of the angle between the third base line (from the point of the umpire) and the runner? Here is a sample prob: Runner is moving from 2nd to 3rd base at a rate of 24 feet per second. Distance between the bases is 90 feet. What is the rate of change for the angle (theta, as described previously) when the runner is 30 feet from 3rd base? Answered by Harley Weston. 





.400 in Baseball 
19991215 

From Nieve Nielson: I have several questions to ask about the probability of getting a .400 in baseball:  What is the probability of a baseball player hitting a .400 in one game, considering that the hitter is up to bat four times?
 What is the probability of a baseball player hitting a .400 in a season, considering that there are 100 games in a season? With the first two questions in mind:
 Considering that baseball has been around for about 100 years, about how many people should hit .400 inthat time?
Answered by Chris Fisher. 





Bases other than 10 
19991206 

From Garret Magin: We are doing a lesson on numbers of other bases than 10. We are working with binary, octal, and Hexadecimal. I was wondering what is used to represent number of different bases other then 16? Does it just continue on with the alphabet and if so what happens when you get to Z. It would be a help if you could answer this because it is really bugging me. And none of the math teachers at my school could let me know. Answered by Claude Tardif and Patrick Maidorn. 





Selecting some players 
19991120 

From Korbin Brown: Roger Craig, during his term as team manager of the San Francisco Giants, received a strange communication from the team general manager, Al Rosen. Mr. Rosen told him to select 25 players according to this formula: 1/2 of the team had to be outfielders and infielders 1/4 of the team had to be starting pitchers 1/6 of the team had to be relief pitchers 1/8 of the team had to be catchers Roger was a bit confused by Al's request, yet complied anyway. How did he do it? Answered by Claude Tardif. 





A Weighty Problem 
19990617 

From A parent: When using a balance scale, weights can be placed on either side of the scale. For example, if a 10 pound weight provides a counter balance to an object and a 7 pound weight, then the object must weigh 3 pounds. What four weights can be used to weigh objects of 1, 2, 3 ... 38, 39, 40 pounds? Answered by Penny Nom. 





Base 2 to Base 10, conversion, convert 
19990508 

From Larry Bader: 10100011_{2} is the same as what number in Base ten? a. 83 b. 128 c. 93 d. 326 e. 163 Answered by Penny Nom. 





Place Value 
19990105 

From Reg: I work in a Section 27 classroom with various grades. I am looking for assistance on how to deliver a lesson on place value:decimal numbers keeping in mind that they need to see it (visual) to comprehend. I am looking for grade 46 level. Answered by Jack LeSage. 





Converting to other bases 
19960206 

From Paul: Converting base 10 numbers to other bases Answered by Penny Nom. 





Opérations de base 
20030705 

From AnneMarie: Je m'appelle AnneMarie et je suis enseignante de 5e année à l'école Domaine des copains de Balmoral au NouveauBrunswick. Récemment, j'ai participé à un concours intitulé: Budweiser King Pack Nascar Hat Promo. Afin de réclamer le prix, qui est une casquette, je devais répondre à une question réglementaire. Il s'agissait d'une phrase mathématique qui se présentait comme suit: 4 x 26  24 / 8 = qui se lit: 4 fois 26 moins 24 divisé par 8 Answered by Claude Tardif. 





des conversions de bases différentes 
20030104 

From Christian: Je cherche désespérément la (les) règle(s) pour réussir des conversions de bases différentes : de base x vers base y. Answered by Claude Tardif. 

