Question: Hi my son Anthony is in Third Grade and the question on his homework that we're having trouble answering is the following:

Name two smaller arrays you can use to find the product. 6 x 9 = 54

What are they exactly asking? Which is the correct answer?

Thank you in advance

Sergio

Hi Sergio and Anthony,

An array is a rectangular arrangement. Think of something like 54 pennies. You can arrange them into 6 rows and 9 columns. This is a 6 by 9 array. (Mathematicians always state the number of rows first and then the number of columns.)

I think what the question is asking is for you to arrange the 54 pennies into two smaller arrays. There are many different answers. One is to make a 4 by 7 array and a 13 by 2 array, since 4 7 = 28 and 13 2 = 26 and 28 + 26 = 54. I am not sure what Anthony's teacher means by smaller. Both of these arrays have fewer pennies but the second has more rows than the original 6 by 9 array. Can you find two arrays where both have fewer than 6 rows and fewer than 9 columns?

Penny

Hi,

By breaking down the numbers you can make it easier to find answers. So that 6 9 = 54 is the same thing as
(3 9 = 27) + (3 9 = 27).

6 12 = is the same thing as
(6 6 = 36) + (6 6 = 36). It makes it easier to find the answer if you don’t know that 6 12 = 72.
If you don’t know that 6 x 6 is 36 you can break it down even further so that it looks like
(3 6 = 18) + (3 6 = 18) + (3 6 = 18) + (3 6 = 18) = 72.

Hope this helps.
Diane