







The difference between the ares of two rectangles 
20160609 

From Ingrid: I am trying to help my son with an area question.
I have the answer, from the solutions, but I cannot figure out how to teach him.
Question:
Two rectangles have lengths 13cm and 19cm respectively.
Their total area is 376cm squared.
If both their widths are whole numbers, what is the difference in their areas?
I know that this is solvable once I determine the widths of the rectangles ,
but how do I go about finding that?
Thanks for your help Answered by Chris Fisher and Harley Weston. 





A procedure for finding a square root 
20150827 

From Tracey: Is there a method/process to determine the square root of a large number?
For example, Tiananmen Square's area is 396 900m sq., what is the side length?
Thank you,
Tracey Answered by Harley Weston. 





Express the HCF of 1232 and 573 as 1232x + 573y = 1 
20090222 

From Anonymous: Express the HCF of 1232and 573 as 1232x + 573y = 1. Answered by Victoria West. 





Discovering the incircle of an irregular polygon 
20070525 

From Joaquim: I've been searching in some books and many websites, but I couldn't find a formula or algorithm for discovering the incircle of an irregular polygon, could you please help me? Answered by Walter Whiteley. 





Greatest common divisor 
20070314 

From Marie: How do I prove this?
Let h be the greatest common divisor of the positive integers a and b.
Show that there exist integers p and q (not necessarily positive) such that
pa + qb = h.
Thanks Answered by Penny Nom. 





Show that 3k+2 and 5k+3 are relatively prime 
20070115 

From Andrea: show that if k is a positive integer, then 3k+2 and 5k+3 are relatively prime Answered by Penny Nom. 





How many children were there? 
20060514 

From Geecee: At a local village gala, the entire population turned up, 500 people. The event raised £3,000. Tickets were priced as follows: £7.48 men, £7.12 women and £0.45 children.
How many children were there? Answered by Stephen La Rocque. 





Finding square roots 
20060412 

From Fehmida: I would like to know about tricks or formulas to do complicated square roots.
ex. square root of 1029 Answered by Penny Nom and Steve La Rocque. 





The Euclidean Algorithm 
20020131 

From Murray: Can you please explain to me why the euclidean algorithm works? Answered by Penny Nom. 





Reduce 79,537/3,623,420 
20011213 

From Eliana: How do you reduce 79,537/3,623,420. Answered by Claude Tardif. 





A calculation with 6 numbers 
20010616 

From Edwin: I'm asked to come with, and program (in Ansi C) an algorithm that calculates all the possible results of a calculation with 6 numbers and one result. For example: I want all calculations with the numbers 3, 3, 8, 8, 2, 9, and with a result of 786. all numbers may be used once, arithmetical operations allowed are +  / *, fractions are not allowed. The problem here is what is a fast method to do this (i.e. what's algorithm that can to this). Answered by Claude Tardif. 





Why does division start from the left? 
20000524 

From Salil Dave: Addition, subtraction and multiplications start with right most digit and proceed left, but division starts from leftmost digits and goes right ... why? Answered by Harley Weston. 





Algorithms for roots 
19960222 

From Charles Hewitt: I have seen an algorithm for finding the square root of numbers. Are there similar such algorithms for higher roots? Answered by Harley Weston. 





Prime numbers 
19960222 

From Charles Hewitt: I would apprecaite it if you could share with me any algorithm to determine whether a number is prime. Answered by Penny Nom. 

