Question

Susan solved 200-91 and decided to add her answer to 91 to check her work explain why this strategy works

Answer 1

Answer:

Property of additive inverse

Step-by-step explanation:

The additive inverse of a number a is -a as:

a + (-a) = 0 = (-a) + a

So, Susan tried to add the additive inverse of her subtrahend 91.

Let's see how it works:

(200-91) + 91 = 200 + (-91 + 91)    (associative property of addition)

= 200 + 0   (additive inverse property)

= 200, the original number.

Hence, her check is correct.

Answer 2

This strategy works because if you subtract one number from another the sum of the two numbers should be the that is being subtracted from. (In this case, it's 200)