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What is the most important thing a student needs to do when adding or subtracting decimals

1. a+b=b+a is an example of the

2. (2x3) x 4 = 2 x (3x4) is an example of the

3. 5 x0 = 0 is an example of the

4. 3+0 = 3 and 4x1=4 are both examples of the

Commutative Property

Associative Property

Zero Property

Identity Property

What do we do with decimals when multiplying?

Example: .05 x.03

Put the steps in order for dividing the following problem. .081/.09

find the number of decimal points in each number. .081 =3 .09 = 2

subtract the number of decimal points of the dividend and the divisor. 3-2 =1

Turn both decimals into whole numbers. .081- >81 .09->9

divide the whole numbers. 81 / 9 = 9

Move the decimal on the whole number to the left by the difference of the decimal points. 9. -> .9

0.9 x 0.7

A

63

B

6.3

C

.63

D

.063

10 x 0.05

A

0.50

B

50

C

5

D

.05

0.050/.1

A

0.05

B

50

C

5

D

.5

4.5 / 5

A

.9

B

9

C

0.09

D

90

7.3 x 7.0

A

511

B

.511

C

5.11

D

51.1