Tell how the Commutative and Associative Properties of Addition can help you evaluate the expression using mental math. $2-7+\left(-2\right)$

Answer 1

The Commutative Property of Addition allows you to rearrange the order of the numbers being added without changing the sum. The Associative Property of Addition lets you group numbers in any order without changing the sum.

For the given expression (2 - 7 + (-2)), you can use these properties to rearrange and group the numbers in a way that makes mental math easier.

Let's apply the properties:

[2 - 7 + (-2) = 2 + (-2) - 7]

Now, you can use the Associative Property to group (2 + (-2) together first:

[ (2 + (-2)) - 7 ]

The sum of (2 + (-2)) is \(0), so the expression simplifies to:

[ 0 - 7 ]

Now, you can use mental math to find the result:

[ -7 ]

So, using the Commutative and Associative Properties, you can quickly evaluate the given expression as (-7).