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 Topic: arithmetic
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An arithmetic sequence 2020-04-04
From ally:
-10 ... last term 35 common difference is 3
(a) find the number of term in the sequence.
i have lost the formula.

Why Mean? 2019-05-08
From Jill:
A group of teachers were trying to figure out why the”mean” is called mean - do you know??
An arithmetic sequence 2019-02-23
From Dalal:
If x+1 and -x+17 are the second and sixth term of a sequence with a common difference of 5, what's the value of x.
An arithmetic sequence 2019-01-31
From sara:
if the 6th term of an arithmetic sequence is 8 and the 11th term is -2, what is the first term?
The number of terms in an arithmetic sequence 2018-06-15
From Don:
how many terms in arithmetic sequence are there if the first term and the last term are 3&59 respectively in common difference is 4?
Gauss' Addition of whole numbers. 2018-04-30
I found this on your site. Question: what is the sum of the first 100 whole numbers?? Is there a different formula if the numbers begin at a number other than one? For example What is the series I want to add is goes from 7 - 53?
An arithmetic sequence 2017-11-30
From yo:
x; 2x+1; 11 are three consecutive terms of an arithmetic sequence.calculate x
An arithmetic sequence 2017-07-17
From abbi:
hi there im a student in 11 grade

ive been trying to do this task but i have no idea how to do it the question is
Find the common difference and the n^th term of the arithmetic sequence if the first term is 4 and the twentieth sum of the terms is 1030

Why does 10x10x10 give 1,000.0000000000001? 2017-04-12
From Randolph:
Hi, On your calculator I found that a box 10 by 10 by 10 inches has a volume of 1,000.0000000000001 cubic inches. Can you explain the numeral 1 thirteen places past the decimal? Thanks, Randy
Addition and subtraction base 5 2017-01-29
From BABAWALE:
Simplify 342five +132five-223five
Which term of this sequence has value 8? 2016-07-20
From Lauren:
Hi there

Which term in the sequence -2; -5/3; -4/3 ; -1; ... has a value of 8.

Since term 2 and 3 of this sequence contain fractions which can be converted to recurring decimals. What is the best way to work out the common difference here.

I do however understand that to work out the nth term of an arithmetic series, the following formula Tn = a + (n-1)d. In this series a = -2

Calendar arithmetic 2016-02-14
From Jenalee:
January 1, 2001 is Julian Day 2 451 911 (the number of days that have passed since Day 0, January 1, 4713 BC).

If Julian Day 0 was a Monday, what day of the week was January 1, 2001?

A sequence 2016-01-05
From Mia:
the next three terms in each sequence. 0.4, 0.54, 0.68, 0.82,
Subtraction base 5 2015-08-29
From nakita:
can u explain the quinary subtraction ...
(3000) -(2342) all the numbers are in quinary number system

1 + 2 + 3 + ... + (2n - 1) 2015-01-01
From Brian:
Hi Maths Central
My wife presented me with a query which may have a simple answer, but one that I can’t deduce or explain.

Take the string of numbers, n=1,2,3,4,5…
It seems that n(2n-1) = Sum((1…..(2n-1))
e.g. for n=5, both 5 x 9 and Sum(1….9) equal 45, and so on for other values of n.

Could you please provide an explanation? Does it have an underlying reason and a name?

Brian

An arithmetic progression 2014-11-19
From Gbenga:
In an A.P the difference between 8th and 4th term is 20. The 8th term is 1\2 times the 4th term . Find arithmetic progression..
The sum of the first 50 terms of an arithmetic progression 2014-07-26
From Joshua:
Hello ...my is Joshua...I'm a grade 11 student...I got a question

Calculate the sum of the first 50 terms of an arithmetic progression: 112:98:84

An arithmetic progression 2014-03-31
From Japheth:
The 3rd term of an A.P is 10 more than the first term while the fifth term is 15 more than the second term. Find the first term?
9,-4,6,-8,3,... 2014-03-31
From Alynna:
You are given the following pattern: 9,-4,6,-8,3,...
Create a formula for the nth figure.

I have trouble finding the formula, I need help trying to find it.

An arithmetic sequence 2014-03-20
From Xabiso:
The 10th term of an arithmetic sequence is 28 and the 7th term is 19. Calculate the common difference and the first term of the sequence.
An arithmetic sequence 2014-01-06
From paris:
find the twenty-fifth term of an arithmetic sequence whose first term is 12 and whose common difference is -6
Base 5 arithmetic 2013-11-27
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?
Base 5 arithmetic 2013-10-12
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?
An Arithmetic Progression 2013-10-08
From collins:
In an A.P. the difference between the 8th and 4th term is 20 and the 8th is one and half times the 4th term... what is the common difference and the first term
From monica:
the questions in the homework says change the order or group the addends so that you can add mentally ,find the sum and tell which property you used 120+37+280 and 25+25+30
The sum of all whole numbers from 1 to X 2013-09-06
From Tim:
How do I develop a rule for the sum of all whole numbers from 1 to X when I have no idea how to do this
An arithmetic progression 2013-07-06
From ashok:
the 4th and 10th term a.p respectively 7 and 19 find its 15th term.....
A messy arithmetic expression 2013-02-24
From niiaryee:
(((((5^2*4^3)1/5+9^3/3)+(25+(4*5)/15)^2-10)/10/2)3)))))
An arithmetic progression 2013-02-06
From loberto:
the 3rd term of an a.p is 10more than the 1st term,while the 5th term is 15more than the 2nd term,find the sum of the 8th and 15th terms of the a.p if the 7th term is 7times the 1st term
Mod versus Rem in Turing 2013-01-01
From Eric:
I am a teacher teaching computer science using Turing. I am having difficulty understanding why one would use the mod operator versus the rem remainder operator.

Mod seems to make the resulting sign depend on the sign of the divisor, whereas rem makes the resulting sign depend on the dividend.

Examples:

11 mod 5 = 1 and 11 rem 5 =1
-11 mod 5 = 4 and -11 rem 5 = -1
11 mod -5 = -4 and 11 rem -5 =1
-11 mod -5 = -1 and -11 rem -5 = -1

What I can't understand is why this would matter. For example, -11 / 5 = -2.2 and 11 / -5 = -2.2 get the same result.
So how is a remainder dependent on the sign of one of the parts? What benefit would using one over the other have?

Any insight would be most helpful!

Eric

An arithmetic progression 2012-08-22
From A student:
the 3rd term of an A.PPP is 10 more than the first term while the 5th term is 15 more than the second.find the sum of the 8th and 15th terms if the 7th term is 7 times the first term.
6/2(1+2)=? 2012-02-21
From boyong:
6/2(1+2)=?
An arithmetic expression 2012-01-05
From Jennifer:
1.8 + 3.2 / 0.4 - 4.375 x 0.2
Mean and Average 2012-01-03
From john:
what is the difference between average and mean
The 3rd term of an A.P is 10 more than the first term 2011-11-29
From Olaniyan:
the 3rd term of an A.P is 10 more than the first term while the fifth term is 15 more than the second term. Find the sum of the 8th and 15th terms of the A.P if the if the 7th term is 7 times the first term.
An arithmetic expression 2011-11-28
2/5*-3/7-1/6*3/2+1/14*2/5
Three consecutive terms of an arithmetic sequence 2011-10-30
From Juliette:
Find X when x, 1/2x + 7, 3x -1 are consecutive terms of an arithmetic sequence.
Modular arithmetic 2011-10-30
From Kim:
Hello,
I am editing a resource for students, and I think some of the answers may be incorrect. The text I was given and my questions are in the attachment. Any help you could give would be appreciated.
Thanks,

Kim

- 16 x 6 / -2 2011-09-09
i dont understand how to answer this question ;
- 16 x 6 / -2
i still dont understand it with bedmas
/ = divison

(x^3 + 11x) is divisible by 6 2010-06-24
From PT:
Given that x is a non-zero integer, how do you show that for all values of x, (x3 + 11x) is divisible by 6?

I know it works but how do I answer the "all values of x" part?

4 + 10 + · · · + (6n − 2) 2010-04-21
From Lan:
Find the sum 4 + 10 + · · · + (6n − 2). The answer is 3(n^2) + n. How?
(24x3)+(7x8)-(20/5)+(4x7) 2009-12-01
From Marilyn:
(24x3)+(7x8)-(20/5)+(4x7)
Thought I had the answer but the form says no. Could you solve it for me please.

24 feet of pipe in 3 pieces 2009-10-09
From Sam:
I had a carpenter being a smarty pants with me. Question: I have a 20ft piece of pipe. I need three equal lengths cut. What is the measurement of each cut? He told me the answer right away because he knows the measuring tape like the back of his hand. The answer is 6'8". Is there an equation I can use to get the answer quicker than him looking at his tape measure?
How many terms are there in this sequence? 2009-09-28
From tabby:
How many terms are there in this sequence?
5,1,-3,...,-111

Arithmetic Sum & Sequence 2009-09-01
From Alice:
Find the 24th term of this sequence 6.8,8.0,9.2... Find the sum of the first 21 terms
Subtraction base 5 2009-08-09
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

Finding the Common Difference and Number of Terms of an Arithmetic Sequence 2009-07-24
From Juan:
In an arithmetic sequence, the first term is -2, the fourth term is 16 and the nth term is 11,998 A. What is the common difference? B. What is the value of n.
WHAT IS 8+4(22-7) 2009-05-05
From ROB:
WHAT IS 8+4(22-7)=
The middle term of an arithmetic sequence 2008-12-15
From Leigh:
Find the sum of the first fifteen terms of an arithmetic series if the middle term is 92
An arithmetic series 2008-10-17
From Laura:
In an arithmetic series 5+9+13+...+tn has a sum of 945. How many terms does the series have? What formula do I use?
Bags of pennies 2008-10-11
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.
Four weights 2008-08-25
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?
The product of the digits of a four digit number 2008-07-26
From Pete:
I am a student preparing for a competition and this was one of the prep problems: The product of the digits of a four digit number is 6x5x4x3x2x1. how many such numbers are there with this property?
Remainders 2008-06-30
From vivek:
what is the remainder when 2050*2071*2095 is divided by 23 ? this question needs to be done in as less time as possible.
1?2?3?4 = 7 2008-04-25
From john:
1 2 3 4 = 7

The numbers have to stay in order of 1234 and when added,subtracted,multiplied or divided they have to equal 7.

1+15=20-? 2008-04-25
From MUBARAK:
1+15=20-?
Base 5 arithmetic 2008-03-06
From Jana:
Hello, my name is Jana, i have asked a question here previously about how to count in base-5. 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 base-5 numbers. it is just a bit hard for me. So do you think you could explain how to do a sum in base-5 and how to do a multiplication sum. Please help...Thankyou Jana!!
An arithmetic expression 2008-03-05
From Kasani:
evaluate the expression: -2^-1[-14 - 4(-6)] - (7 - 3)
10 - 3 + 2 2008-02-21
From Amrit:
what 10-3+2

is it 5 or 9

The nth term 2007-10-18
From shannon:
Ok , what i am having problems with is the nth term. I get how the numbers come together, but i am having trouble with finding the nth term.
Solving arithmetic problems in the right order (BEDMAS) 2007-10-05
From Kim:
3+4x2-(10 divided by 5)= what?
The nth term 2007-09-09
From Conor:
Please can you help me with this question on the subject of the Nth term. 3.5, 5, 6.5, 8, 9.5

5.1, 7.2, 9.3, 11.4...

2(8-3)+2^2 2007-07-30
From Nikki:
2(8-3)+2²
How many terms in this sequence? 2007-06-11
From Jesse:
How do I find how many terms are in the sequence? 51, 48, 45, ...., -75
Answered by Stephen La Rocque and Penny Nom.
Arithmetic means and geometric means 2007-04-04
From Dani:
Hi! I was just wondering why the arithmetic mean of sets of numbers is larger than the mean proportional of the same numbers? Thanks! Dani
Arithmetic Series 2007-02-18
From Krista:
Question- The sum of the first 4 terms of an arithmetic series is -8 and the sum of the first 5 terms is 500. Determine the sum of the 3 terms.
5,8,11,14,17 2007-01-18
the sequence i was given was 5,8,11,14,17 what is the nth term and what is the 10th term ?
An arithmetic series 2006-11-28
From Jillian:
Find the sum of 21 terms of an arithmetic series that has an eleventh term equal to 30.
Arithmetic with base -2 2006-11-26
From Yuva:
can we do arithmetic ,base -2. If yes, how and if not, why.
The sum of 2000 consecutive integers is 1000 2006-10-29
From Matias:
if the sum of 2000 consecutive integers is 1000, then the sum digits of the greatest of these 2000 integers is?
Squaring numbers 2006-10-08
From Timothy:
did anyone ever try to teach that the easiest way to find the next square in a group of numbers is to add the next odd number in the sequence. for example: 1 squared is 1, 2 squared is 4,difference of 3.the next odd number is 5 so the next square would be 4 +5 or 9
Answered by Paul Betts and Penny Nom.
what is 8+(-2)(-5)/4-(-1)-4(-2+3) 2006-09-08
From Jordan:
what is 8+(-2)(-5)/4-(-1)-4(-2+3)
From Lisa:
When I have a total that is the sum of consecutive numbers, how do I figure out what the numbers are?
Arithmetic and Geometric Sequences 2006-04-19
From Skye:
If the 1st, 4th, and 8th terms of an arithmetic sequence are consecutive terms in a geometric sequence, find the common ratio of the geometric sequence.
Arithmetic Sums 2006-04-12
From Angel:
(a) In a particular arithmetic sequence, u6 = 344.5 and u20 = 88.3. Find S28. (b) In a particular arithmetic series, S10 = 495 and S15 = 1005. Express S15 in sigma notation.
(17-5)/3x2 2006-02-26
From A student:
can you help me answer this question (17-5)/3x2
Arithmetic progressions 2006-01-31
From A student:
1)the sum to n terms of a particular series is given by Sn=17n-3n2

a)find an expression for the n term of the series
b)show that the series is an arithmetic progression

2)a particular arithmetic progression has a positive common difference and is such that for any three adjacent terms ,three times the sum of their squares exceeds the square of their sum is 375.Find the common difference

For what divisors can you get a remainder of 8? 2006-01-06
From Thelma:
When dividing a 3 digit number by a 1 digit number, for what divisors can you get a remainder of 8?
(5 + 10) x 2 - 10 = 2005-12-05
From Jessica:
(5 + 10) x 2 - 10 =
An Arithmetic sequence 2005-12-01
From Aana:

The first term in an arihmetic series is 25 and the 3rd term is 19. Find the number of terms in the series if its is 82.

Here's what I did to find d
a+2d=19; 25+2d= 19 ;19-25=2d d=-6/2=-3

This is where I'm stuck. Can you please provide me with some guidance.

Two groups that have equal sums 2005-09-30
From Anita:
using the numbers 1, 2, 3, 4, 5, 6, 7,and 8. how do we divide them into two groups so that they have equal sums?
BEDMAS 2005-09-01
From A student:
I am a student and am wondering about the answer to this question.

56/2(31)

Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: 2005-07-18
Three prime numbers p,q and r, all greater than 3, form an arithmetic progression: p=p, q=p+d and r= p+2d. Prove that d is divisible by 6.
An arithmetic progression 2004-12-24
From A student:
the 4th and 5th term of an arithmetic progration 47 and 52 respactively find
a)d
b)a1
c)a50

Bedmas 2004-10-30
From Gina:
I am just curious whether Bedmas would be used in the following question as it is not in the typical Bedmas format.

Multiply 12 x 24
Divide by 2
Subtract 7

Would we go about doing it in the sequence it is given or in Bedmas ?

1+3+5+...+(2n+1) 2004-09-10
From Emma:
Prove that 1+3+5+...+(2n+1)= (n+1)2
Half way between 2004-09-08
From Ben:
Find the number halfway between the number shown

751,843

The sum of some positive integers 2004-06-07
From A student:
Find the sum of all positive integers not greater than 10000 that are divisible by neither 3 nor 7.
The sum of 4,0,-4..., -156 2004-04-28
From Christina:
find the requested sum of the arithmetic sequence

4,0,-4..., -156

(3x50)+20/5=? 2004-04-03
From A student:

(3x50)+20/5=?

Arithmetic in bases other than 10 2003-10-22
From Kim:
how do you add, subtract, multiply and devide in base 3, base 5, etc?
1 + 1 = 10 2003-09-17
From David:
could you please explain to me how 1+1=10 thanks
Converting from base 10 to base 5 2003-09-10
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.Ư 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.
38 minus 10 plus 12 divided by 4 times 16 2003-04-23
From James:
please help me work this math problem 38 minus 10 plus 12 divided by 4 times 16
Chopping trees 2003-04-19
From Tamara:

The master needs some of the trees (twenty, to be exact) at the back of his spooky old mansion cleared to make way for a new evil laboratory, so he decides to send some his slaves to do the work for him.

He initially sends out four of his men, armed with axes, to chop the trees down. Due to the fact he is very impatient, every ten minutes he sends out another man to help with the work.

Assuming that it takes one man 30 minutes to chop down 1/3 of a tree, how long till all twenty trees are chopped down?

How many hits? 2003-04-06
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.

Finite differences 2003-02-10
From Jenny:

I need to find a formula that will work with any number.
I am finding the volume of a 3d cross- shape. Here are my results so far:

```Term Number      0   1    2    3     4      5
nth term         1    7   25   63   129    231
1rst diff           6   18   38   66     102
2nd diff              12    20   28   36
3rd diff                  8     8    8
```

I can't seem to find a formula that will work with any number. Any help would be much appreciated.

The sum of the first 1000 even integers 2003-02-06
From Jill:
What is the sum of the first 1000 even integers?
Arithmitic sequence 2003-02-01
From A student:
I am having problems solving this arithmetic sequence... 1, 5, 10, ___, 50, 1.00, ___, 10.00, ... I believe the answers to be 25 and 5.00 but I can't figure why.
1+2+3+...+500 2003-01-31
From Brian:
What is the sum of the numbers from 1 to 500 inclusive?
5x(-2)-32/8 2003-01-13
From A student:
I'm having problems solving this question:
5x(-2)-32/8

Integer arithmetic 2002-12-05
From A student:

I am just learning about integers. Can you show me in a way I might understand....My teacher can tell me what is required to do the math, but it just doesn't make sence to me.

(+4) - (-3) =+7

Why is the answer not +1

Chisanbop 2002-11-07
From Paul:
I'm trying to find the book/books that explain this system? I have one small book that explains the very beginning of the system, but covers only about 10 to 20%. I'v tried several book sellers and have had no luck.
Sums of evens 2002-09-14
From Rosa:
How do I find a geometric way to easily compute sums of consecutive even numbers 2 + 4 + 6 + ....
Answered by Leeanne Boehm and Harley Weston.
7+8+9+...+1000 2002-09-11
From Shirley:
My question is what is the formula for adding up numbers when you don't start with number 1? For example 3 + 4 + 5 + 6 = 18. But how could you arrive at the answer without adding all the numbers?
38-10+12divided by4multiplied by 16 2002-08-30
From Brenda:
my math question is as follows: 38-10+12divided by4multiplied by 16=?
Order of operations 2002-07-18
From Danna:
I would like to know how to solve this type of problem; I already have the answer.

Problem: 2 [5 (4 + 6) - 2] = 96

Also, what do you call this type of problem? Thanks a lot.

8/13*26/27 2002-05-01
From Arias:
8/13*26/27=
Arithmetic progressions 2002-04-24
From David:
I have been searching everywhere for the formula to mathamatical progression.
Take It! 2002-04-03
From Bryan:
You are playing Take It! for \$180,00 with a total stranger. There are 180 identical balls in a big vase. Each player in his turn, reaches into the vase and pulls out 1,5,or8 balls. These balls are discarded. The player who takes the last ball from the vase wins the \$180,000. A flip of the coin determines that you will go first. Are you glad? How many will you take out on the first move, and how will you proceed to win the prize?
Making 24 2002-01-17
From Renee:
My 4th grade daughter and I need to find a simple math sentence using 5, 5, 3, & 7 to equal 24. You can add, subtract, divide or multiple.
Papy's Computer 2002-01-11
From Mary-Anne:
My second-grade 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.
Painting walls 2001-12-12
From Rizwan:
3 sixth graders painted 4 walls in 3.5hrs. At that rate, how many walls would they paint in 7 hrs.
Recalling the basic facts 2001-12-12
From A parent:
My son is in 4th grade and is a very bright student. He is in the gifted program and makes straight A's on his report card and has through out school so far. My question is how can I teach him to memorize his basic math facts? He does well in math, but when he is placed in a times situation for completing math fact sheets he freezes up. He can not recall the basic facts when questioned at any other time either. He will calculate the answer in his head, like 6 + 3, but he can't just come out with the answer quickly. How can I help him?
Negative times negative is positive 2001-10-26
From Mary:
I have a question about adding and multiplying positive and negative numbers. When we add two negative numbers the answer is negative BUT when we multiply two negative numbers the answer is positive. I don't understand. Why?
Arithmetic sequences 2001-09-10
From Rachel:
I can't seem to figure out a problem that deals with arithmetic sequencing. This is the question: The 5th term in an arithmetic sequence is 1/2, and the 20th term is 7/8. Find the first three terms of the sequence. I attempted this problem with the formula: An = a + (n-1)d (where the n represents the nth term, a is the first term, and d represents the common difference) I keep getting -9.5 for the first number, and then 3/120 as the common difference between the numbers. But as I have figured it, the sequence is getting greater and greater, and my data does not go with the terms given.
Geometric and arithmetic sequences 2001-01-26
From Garry:
what are the equations for geometric and arithmetic sequences?

also, what are the equations for finding the sums of those series?

Answered by Leeanne Boehm and Penny Nom.
Order of operations 2000-11-26
From Margaret Pratt:
My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+1-5= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated.
Arithmetic in base 5 2000-09-20
From Lesley Emerson:
my daughter is 9 and has been aske to solve the following in base 5

3+2
4+10
.
.
.

Order of operations 2000-09-19
From Nicole:
the problem is, 4x8-18 divided by 6= do you solve this by doing 4x8=32 then by dividing 18by 6= 3, then subtracting 3 from 32 = 29? If not what is the order of operation?
7 - - - - 77 2000-09-13
From Peter:
Does anyone know how to solve the following:
7 _ _ _ _ 77 ?

I have to find the missing values.

Answered by Chris Fisher and Walter Whiteley.
How many 17's and 19's total 1000? 2000-09-07
From Jonathan:
My question is: what 2 numbers would multiply 17 and 19 for a total of 1000. The numbers should not contain any decimal.
The sum of the squares of 13 consecutive positive integers 2000-08-25
From Wallace:
Prove that it is not possible to have the sum of the squares of 13 consecutive positive integers be a square.
Find the next term 2000-08-12
From Ashley:
8,27,64
I need the next three numbers & I can't figure it out. I have worked on this all day.

Why does division start from the left? 2000-05-24
From Salil Dave:
Addition, subtraction and multiplications start with right most digit and proceed left, but division starts from left-most digits and goes right ... why?
The number of seats in an auditorium 2000-05-16
There are 10 students in the first row of seats in an auditorium 12 in the second 14 in the third and 2 additional in each seat. The total number of rows is 40. I know the answer is 1960 can you please show me the formula step by step.
Finding a formula 2000-05-05
From Erica Hildebrandt:
If a farmer has a field and his plots are laid out in the following grid where each # represents a plot:
 4 5 12 13 20 3 6 11 14 19 2 7 10 15 18 1 8 9 16 17

Of course the plot numbers aren't meaningful as I have described above. In fact they may not be numbers at all. The only constants I have are the total number of rows and columns. Using the total number of rows and columns and my current position row and column, how can I write a formula that tells me column 3 row 3 = 10, column 4 row 2 = 14, etc. I can see the pattern but can't quite get the formula. I believe I will need 2 different formulas one for even and one for odd rows.
Answered by Paul Betts and Penny Nom.

In adding fractions, how do I rewrite the fractions so that the denominators are equal? The problem is 3/4 + 1/6 =
The other problem is 11/18 + 4/9 =

Borrowing 2000-04-17
From A college student:
How would you explain borrowing to an elementary school student?
Star-multiplication 2000-04-07
From Greg Potts:
I have this question to answer and I don't know where to start. 1*9=0, 9*8=72 and 2*8=9, then 9*9 =?
A negative times a negative 2000-02-29
From Michael J. Butler :
I have reviewed the answer in relation to the question of why (-3)x(-2)=6; however, I am still not able to properly explain the reasoning to my son, Jonathan, who is in grade 7. I want him to understand the reason for the rule that the multiplication or division of two negative numbers equals a positive number. Can you help?
Compatible numbers 2000-01-27
From Angie:
Use compatible numbers to estimate each product and quotient.
23*1/2
1/3*11

Order of operations 2000-01-16
From Dorothy:
I was wondering if you could tell me where I can get some info. on how to solve the following problem. I was given the answer but I don't know how it is solved.

4+2x(6x2)-5=23

Four fours 1999-09-09
From Roger:
I need help with a math problem my child asked me about I guess in her 7th grade math class they were told to come up with a answer from 1-10 only using four 4's and she got stuck on the problem that needs to be equal to ten, she asked me and I couldn't help her it's sad so if you could give me the problem and and answer so i could explain it to her I would really appreciate it.
A double negative 1999-09-01
From Dennis:
If b = -2 what does -b = ? As in (a + 8.5) - [(-b) + |c|] a = 1.5, c = -1.7
Division by a negative 1999-08-19
From Sangeeta B.:
56/-8
A Weighty Problem 1999-06-17
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?
Base 2 to Base 10, conversion, convert 1999-05-08
101000112 is the same as what number in Base ten?

a. 83
b. 128
c. 93
d. 326
e. 163

Roman Numerals 1999-04-29
From Michelle Jenkinson:
Someone proposed this question to me and I do not know the answer, so I was wondering if you could help. How, using Roman Numeral, did people add, subtract, multiply, and divide with no zero or negative numbers?
Divisibility by 9 1999-02-21
From Razzi:
I've been having a hard time trying to solve the following problem and I was wondering if you could help me.

For any positive integer a let S(a) be the sum of its digits. Prove that a is divisible by 9 if and only if there exist a positive integer b such that S(a)=S(b)=S(a+b).
Answered by Chris Fisher and Harley Weston.

Modular Arithmetic 1999-02-04
From Leslie Kupper:
I am trying to do a project on modular arithmetic. I was wondering if there were any websites that include a sample lesson plan on modular arithmetic for any grade level. Let me know where and how to find them. Thanks.
Arithmetic Progressions 1998-11-12
From Gerry Boser:
It has been years since I was in school and I can't remember if there is a formula for the following problem:

If you deposit \$1.00 on the first day of the month, \$2.00 on the second day, \$3.00 on the third day . . \$31.00 on the last day of the month, how much do you have in the bank?

Now will this formula also work if it was, \$0.25 (then day two you would deposit 2x \$0.25 or \$0.50, day three you would deposit 3x \$0.25, \$0.75. . . ). Will it work with any denomination??

Thank you for your time. I promise I'll write this one down for future reference. . .

Dividing a Class 1998-10-01
From Tom Barker:
My eighth grade niece called with the following homework problem:

A teacher wanted to divide her class into equally numbered groups. She tried to divide the class into groups of two, but was one student short. She tried to divide the class into groups of five, but was one student short. She tried to divide the class into groups of seven and was successful. What is the least number of students that were in her class?

I know the answer is 49, but don't know how to prove it. I must be getting old if I can't solve eighth grade math problems. Your assistance would be appreciated.

Sequences and series 1998-05-27
From Michael Le Francois:
The sum of the first ten terms of an arithmetic series is 100 and the first term is 1. Find the 10th term.

The common ratio in a certain geometric sequence is r=0.2 and the sum of the first four terms is 1248 find the first term.

Clock Arithmetic. 1998-03-09
From Joann Dixon:
What is clock mathematics?
Integer Problems. 1997-09-15
From Eric Kowalsky:
1. 5(-4)-[3(-6)+(-3)-4(2(-4)-7)]+3(-8)=

2. -2[-7-3(4)+5-2(-1)]+3(-6+8)=

3. 4[-6(-2-7)-5(7+2)]=

4. -7(-4)-2[-3(-4+6)+6(7-3(-4))]
P.S. Thank you very much.