Question

Describe the mental math steps you would use to find 7(42) (this is the distributive property by the way. :] )

Answer 1

Answer: 294

Break up 42 like so: 42 = 40 + 2

Then we can say,

7*(42) = 7*(40+2) = 7*40 + 7*2 = 280 + 14 = 294

The mental math part is knowing that 7*4 = 28, then you add on a zero to get 7*40 = 280. This is added to 7*2 = 14 to get the final answer above.

Answer 2

multiply 7 by 42

= 294

42 x 7 can be done as mental math, but that is challenging for some people.