Question

5. Maria writes the expression below.

21 + 3 + 6 + 9 − 3
Which expression could be shown to be equivalent to Maria's expression based on the commutative property of addition?

Answer 1

An equivalent expression to Maria's 21 + 3 + 6 + 9 - 3, using the commutative property of addition, could be rearranged to 3 + 21 + 9 + 6 - 3.

Step-by-step explanation:

The commutative property of addition states that the order of numbers being added does not affect the sum. That is, for any numbers A and B, A+B is equivalent to B+A. Using this property, we can rearrange the terms in Maria's expression 21 + 3 + 6 + 9 - 3 to arrive at an equivalent expression.

We need to keep in mind that subtracting a number is the same as adding its negative; therefore, subtracting 3 can be seen as adding -3. Knowing this, we can freely rearrange the positive terms using the commutative property while keeping the subtraction as the addition of a negative.

An example of an equivalent expression to Maria's, using the commutative property, could be 3 + 21 + 9 + 6 - 3.