Question

To add 20.4 + 3.75 + 4.25, Crystal first added 3.75 and 4.25. Which property did Crystal use to add mentally?

Answer 1

Answer:

Associative Property of Addition

Step-by-step explanation:

From the list of given options, option A correctly answers the question and this is because

$a + b + c = a + (b + c)$ --- (1)

or

$a + b + c = (a + b) + c$ --- (2)

The above illustrations only apply to Associative Property of Addition

In Crystal's case:

$20.4 + 3.75 + 4.25 = 20.4 + (3.75 + 4.25)$

This can be compared to (1) above

Hence;

Option A answers the question