What is 4 x 16 using distributive property

Question

This question is about using distributive propertys, which i do not understand it is not a word problem but it is a grade!

 

Answer 1

4 x 16 using distributive property means we are to write 16 probably as 10 + 6

 

Therefore 4(16) = 4(10+6) = 40 + 24 = 64

 

Why do this??

 

If you think of 16 as 10 +6 the mental math becomes a lot easier

 

For example ask your self what is 4 x 10  what is 4 x 6  and then add the numbers together.

 

Let me give you another example:

 

What is 7(19)  

 

Without writing we can mentally think of 19 as 20 - 1

 

Now let's do mental math

 

What is 7 x 20

 

What is 7 x 1

 

140 - 7 = 133