







Vectors 
20190906 

From Kayla: Hi!
Due to time constraint issues, we skipped vectors in PreCalc last year. However, I'm attempting to complete my AP Physics summer homework and there are 3 problems with vectors. As I explained, I have no idea even where to begin and as such I need some help.
Problem 1:
A plane flying at 90° at 45 m/s is blown toward 0° at 62 m/s by a strong wind. Find the plane's resultant velocity.
I have tried all sorts of online calculators but none are providing me with a formula I can use to solve this problem on my own.
Problem 2:
If you walk 367 m North and 785 m West what is your total displacement from your original location?
What is the problem asking for when it says displacement?
Problem 3:
A plane travels on a heading of 127.0° at a velocity of 25 km/hr. What are the horizontal and vertical components of the plane's velocity?
As you know already, I have never done vectors so I don't know what horizontal and vertical components of velocity are.
Thank you So Much for your help!! I am struggling!!
 Kayla Answered by Penny Nom. 





Converting decimals to common fractions 
20180508 

From Ruth: what does the 0 represent in .018 versus the decimal .180? As in, changing these to fractions? Thank you. Answered by Penny Nom. 





A five digit number 
20161012 

From Massa: Explain why any four digit number is less than any five digit number? Answered by Penny Nom. 





A place value drawing 
20160224 

From Kristin: Make a place value drawing of a number that has
double the number of tens as ones and three times
the number of thousands as hundreds write the number. Answered by Penny Nom. 





A barge of triangular cross section 
20140818 

From tushar: a barge of triangular cross section is 20m long 12 m wide and 6m deep.its floats in SW at a draft if 4m find its displacement Answered by Penny Nom. 





A six digit number 
20140630 

From anupam: hi,
my daughter asking a solution for the below question, kindly help.
Write the smallest 6 digit number wit digits ( 2,4,3,0,5,7).
plz this is an urgent requirement.
regards,
anupam Answered by Penny Nom. 





An arrow is shot straight up in the air 
20121206 

From heather: The skywalk is a glass bottomed platform that hangs over the edge of the Grand Canyon and is suspended 4000 feet above the floor of the canyon. If a tourist shot an arrow straight up in the air from the observation platform, the arrow's height could be modeled by H(t) =16^2 + 240 + 4000 where H(t) is the height of the arrow above the canyon floor in feet t seconds after being shot, t>0.
(a) Find H(5) and explain its meaning Answered by Penny Nom. 





Transposition error 
20121203 

From Carol: What is the correct term for when a child writes 61 instead of 16, or 83 for 38when they switch the place values of a number? Answered by Chris Fisher. 





Expanded exponential form? 
20120612 

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





Displacement 
20111217 

From faisal: a helicopter takes off and travels 300 km due north then returns to its landing field. what is its displacement? Answered by Penny Nom. 





Rounding 
20111214 

From seth: A decimal number rounded changed to 23.7 after it was rounded.
Give a decimal number that is less than 23.7 and another that is greater than 23.7 that each round to 23.7.
Explain to what place each number was rounded. Answered by Penny Nom. 





Expanded form 
20111012 

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





Place value 
20110920 

From Ivana: the digit in the ones place is a hand with out a thumb(4)
2) the digit in the thousands place is 2 less than the digit in the one's place.
(42=
3) the digit in the ten's place is the sum of 2 and 6 (2+6=
4) the digit in the hundreds place is what you get when you get when you subtract 5 from the digit in the ten's place (ten's5=
what is the number? Answered by Penny Nom. 





What does 163,100,000 look written in words? 
20110322 

From Alicia: What does 163,100,000 look written in words? Answered by Penny Nom. 





Math in the workplace: nursing 
20100524 

From Taylor: How is math used in the workplace  Nurse Anesthetist? Answered by Penny Nom. 





What number has 5 hundreds and 12 tens? 
20081021 

From kellee: What number has 5 hundreds and 12 tens?
I would say the number is 620. But, my daughter thinks that is wrong. Answered by Harley Weston. 





Hundreds, tens, and units digits 
20080905 

From Cynthia: write an expression for the value of a threedigit number whos hundreds, tens, and units digits are x, y, and z, respectively Answered by Penny Nom. 





3D Vectors 
20080722 

From jenina: 1. The summit of a mountain, 2450m above base camp, is measured on a map to be 4580m horizontally from the camp in a direction 32.4º west of north. What are the components of the displacement vector from camp to summit? What is its magnitude? Choose the x axis east, y axis north and z axis up. Answered by Janice Cotcher. 





Units digit 
20080702 

From seemachauhan: How to find unit digit of various numbers and what are unit digits? Answered by Penny Nom. 





The volume of a stone 
20080417 

From sara: a rectangular tank 30 cm long and 20 cm wide is filled with water to a depth of 8 cm. When a stone was put in, the water level rose to 11 cm. Find the volume of the stone. (Assume that the stone is completely under water.) Answered by Penny Nom. 





Place value 
20071027 

From eric: True or False:
In the number 378, there are 3 hundreds, 7 tens, and 8 ones. Answered by Penny Nom. 





The largest number you can add ... 
20071026 

From Dryden: What is meant by asking what is the greatest number you can add to that number without having to regroup in any place? Answered by Penny Nom. 





I have a 6 digits 
20070928 

From Kim: I have a 6 digits. My hundredthousands digit is 1 less that my ones digit, 8 more than my thousands digit, twice my tens digit, and 4 times my hundreds digit. My tenthousands digit is 0. What number am I? Answered by Stephen La Rocque. 





Tens and ones 
20070916 

From julia: My son has come home with a math question "what i know about 10s and 1s" we're totally stumped any information you can provide would be greatly appreciated Answered by Harley Weston. 





A place value chart 
20070912 

From glenwood: draw a million chart then place the following numbers in the proper place.
one hundred and nine million, seven hundred and twentythree Answered by Penny Nom. 





What number am I? 
20070811 

From Belinda: What number am I? My millions digit is 4. My billions digit is two time =
my millions digit. My hundred thousands digit is two more than my =
millions digit and three more than my ones digit. My ten millions digit =
is one less than my ones digit. My other digits are zero. Write my =
short word form. Answered by Penny Nom. 





Is zero a number or a place holder? 
20070409 

From Chris: Is zero a number or a place holder? Answered by Penny Nom. 





Throwing a stone downwards 
20070112 

From Momo: a stone is thrown vertically downward with an initial speed of 14m/s from a height of 65 m above the ground. A) how far does the stone travel in the first 2.0 s? B) what is the stone velocity just before it hits the ground? Answered by Stephen La Rocque. 





Place value, coins and money 
20061212 

From Emily: I was wondering what the best way would be to teach place value using coins and money. I have used base ten blocks already and am looking for a way to integrate money, perhaps on a place value chart and perhaps using decimals. Answered by Diane Hanson. 





Place value 
20061012 

From Sue: We have extended the place value chart out 14 places and want to know what comes after hundred trillions? Answered by Stephen La Rocque. 





Whats the value of the digit 7 in 756,809? 
20050914 

From Anastasia: Whats the value of the digit 7 in 756,809? Answered by Penny Nom. 





Four and five digit numbers 
20040921 

From Josy:
The question I have now in front of me is....Is a 4digit number always less than a 5digit number?
Hi Josy,
The digits in order are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Thus the largest four digit number is 9999. The smallet 5 digit number is 10000.
Penny
Go to Math Central
Answered by Penny Nom. 





Forty balls are placed in a bag 
20040619 

From Sheila: Forty balls numbered 110 are placed in a bag and four are drawn at random. What is the probability that the first ball drawn is between 110 (inclusive) the second is between 1120, the third is between 2130 and the last is between 3140? Answered by Penny Nom. 





Place Value 
20040425 

From Santosh: Q.
Write the Place value of the digits in the following numerals.
1. 5 in 54
2. 3 in 63 Answered by Penny Nom. 





The digits in 349 
20030912 

From Franik: in the number 349, which number has the least value, and why? Answered by Penny Nom. 





Round to hundredths 
20021119 

From Brittany: Can u tell me how to do a problem like this:
35 divded by 4.8= Round to hundreths. Answered by Penny Nom. 





Rounding 27.27 
20021103 

From A parent: If you have a problem 27.27 and you need to round to the first 7 the answer would be 27 Would 27.0 be acceptable as well or is it completely wrong. Answered by Penny Nom. 





The number of decimal places in 1 over a power of 2 
20020912 

From Allan: Does anyone notice that the maximum number of decimal place of the number 2 dividing 1 and its increment (4, 8, 16...etc) is the same as the power of number 2? eg. 2^{2}=4, thus the max number of decimal of ^{1}/_{4}=0.25 which is 2 decimal place and 2 is the number of power of 2 take 64 as example: 2^{6}=64, and take ^{1}/_{64}=0.015625 which has 6 decimal place (and is the power 6) Is there such a law in math? If yes, can you tell me what it is? Or is this my discovery? Answered by Paul Betts. 





What is a group of three numbers called in a large number? 
20020115 

From Laurie: What is a group of three numbers called in a large number? My son has this question on his 4th grade worksheet. I've taught middle school math for 7 years and nver heard of it. Answered by Paul Betts. 





Scoring a college placement test 
20010926 

From Carmen: A college placement test consist of 75 multiplechoice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers onequarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong? Answered by Penny Nom. 





Place value chart 
20010111 

From Charles: Can you send me a pictorial example of a place value chart? Answered by Harley Weston. 





How many tens are in 400? 
20001107 

From A student: How many tens are in 400? Answered by Penny Nom. 





Grade 4 curriculum 
19990209 

From John: My daughter is in grade 4 and her math teacher has asked her to write out the number 1 to 10,000. She is currently at 4567 and is sick of it. When I complained that this was not a usefull exercise she said that the Ministry of Education curriculum requires this and gave a photocopy of the page. It states: "read and write whole number to 10,000 in standard, expanded, and written forms (eg., 9367=9000+300+60+7 = nine thousand three hundred sixtyseven). Has the teacher interpreted this the wrong way? Thanks John PS. Do you have a web address for Ontario Math and Science Teachers organization? Answered by Jack LeSage. 





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. 





Billions and more! 
19970915 

From Mahabir B. Gupta: I would like to know how you americans write the number 1 billion. Do you say "One thousand million"..can you answer by giving me examples? 1,000,000> 1 million 1,000,000,000>1 billion Why is it that in spanish it is different? Answered by Penny Nom. 





Thousands, millions, billions and trillions 
19960822 

From Blaine: What are the names of the periods in groups of numbers like 123,456,789. I need to know the names of them for school. I already know the first ones: units thousands millions billions trillions. Answered by Penny Nom and Diane Hanson. 

