







Arrays 
20100909 

Susan pose la question : I'm a lawyer but evidently incredibly stupid at 4th grade math. . . .Question: cover a tabletop with 9 rows of square tiles with 9 squares in each row. How many tiles cover the tabletop? Then, the paper shows a 9x9 array and asks how it is used to solve the problem. My daughter wrote 9x9=81. The next question is "what are the products of the two smaller arrays?" ???? There are no other arrays  are we to make smaller arrays from the 9x9? how? Robert Dawson lui répond. 





Pairs of prime numbers 
20031013 

Nikolas pose la question : Use pairs of prime numbers to find all the numbers less than 50 that have only two prime factors. Make an organized list. Penny Nom lui répond. 





1575 
20030313 

Sharyn pose la question : find 6 integers that when multiplied with each other equal +1575 and when the same integers are added together equal zero. there are more positives than negatives and one of the numbers is a double digit between 10 and 20 Penny Nom lui répond. 





Multiplying vectors 
20011022 

Murray pose la question : Could you please explain why a vector times a vector is a scalar and how to derive the formula vector a * vector b = ab cos(a,b) Harley Weston lui répond. 

