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### Properties of Numbers

• To commute means “to change places”; this helps to explain the commutative properties of addition and multiplication: a + b = b + a and a • b = b • a.
• To associate means “to gather in groups”; this helps to explain the associative properties of addition and multiplication: (a + b) + c = a + (b + c) and (a • b) • c = a • (b • c).
• The properties of addition and multiplication often let you do mental computations more easily.
• The Commutative Property, the Associative Property, and the Identity Property apply to both addition and multiplication of rational numbers.

## 7.4 + 10 + 3.6 =

• 7.4 + 3.6 + 10
• 11 + 10 =

## 21 + 5 + 39 + 5 =

• (21 + 39) + (5 + 5) =
• 60 + 10 =

## 3 + 16 + 87 + 14 =

• (3 + 87) + (16 + 14) =
• 90 + 30 =

• 25 ×30 ×17 =
• 750 ×17 =

• 2 ×5 ×180 =
• 10 ×180 =

• 25 ×11 =

## Brendon bought a scarf for \$ 3.65, a donut for \$ 2.50, and a briefcase for \$ 26.35. How much did Brendon spend total?

• \$ 3.65 + \$ 2.50 + \$ 26.35 =
• \$ 3.65 + \$ 26.35 + \$ 2.50 =
• \$ 30.00 + \$ 2.50 =

## Larissa bought 17 bananas, 34 strawberries, 6 apples, and 53 cherries. How many fruits did she buy total?

• 17 + 34 + 6 + 53 =
• (17 + 53) + (34 + 6) =
• 70 + 40 =

## Gregory ran 4 miles on Monday, 7 miles on Tuesday, 6 miles on Wednesday, 9 miles on Thursday, 1 mile on Friday, 1 mile on Saturday, and 2 miles on Sunday. How many miles did he run this week?

• 4 + 7 + 6 + 9 + 1 + 1 + 2 =
• (4 + 6) + (7 + 1 + 2) + (9 + 1) =
• 10 + 10 + 10 =

## There is a pie - eating contest. Jessica ate 9 pies, Trevor ate 15 pies, George at 11 pies, Natalie ate 5 pies, and Luke ate 10 pies. How many pies were eaten total?

• 9 + 15 + 11 + 5 + 10 =
• (9 + 11) + (15 + 5) + 10 =
• 20 + 20 + 10

### 50 pies

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.