3 x 42 rewrite using distributive property then find the product

Question

Please give me the answer I need help with my homework & I wasn't at school when my teacher taught how to do this :( =Sad emoji

 

Answer 1

Mark - But you can still use the distributive property to make the multiplication easier to do mentally.

 

Javoen - Since we can break up bigger numbers like 42 into smaller ones using addition, we can rewrite a problem like 3 x 42 into 3 x (40 + 2).  Then using the distributive property, we can do (3 x 40) + (3 x 2) = 120 + 6 = 126.

 

It can also be used with subtraction.  For example:

 

5 x 89 = 5 x (90 - 1) = (5 x 90) - (5 x 1) = 450 - 5 = 445.

 

Hope that helps!  :)  =Smile emoji