Question

school supplies at a local school supply store, graphing paper costs $1.75, a mechanical pencil costs $0.90, and a pack of pencil grips costs $3.25. use mental math and the associative property of addition to find the total cost if one of each item is purchased.

Explanation:

Step1: Recall associative property

The associative property of addition states that $(a + b)+c=a+(b + c)$. We want to find $1.75+0.90 + 3.25$.

Step2: Rearrange the sum

We can rewrite the sum as $(1.75+3.25)+0.90$ because it is easier to add $1.75$ and $3.25$ first.
$1.75+3.25 = 5$.

Step3: Add the remaining number

Then we add $0.90$ to the result. So, $5+0.90=5.90$.

Answer:

$5.90$