6th Grade Rational Operations

Add Decimals

1

2.45 + 1.32

3.77

2

5.8 + 2.14

7.94

3

2.456 + 1.789

4.245

Subtract Decimals

1

8.75 − 3.42

5.33

2

20.0 − 7.84

12.16

3

40.000 − 18.625

21.375

Multiply Decimals

1

What do you do with the decimal point when you multiply fractions?

Give an example.

Ignore it, then add it back later.  You need to count the decimal places in the factors and then put it in the product.

2

1.2 × 0.5

0.6

3

4.2 × 1.3

5.46

4

5.06 × 2.3

11.638

Divide Decimals

1

What do you do when you have a decimal in the divisor?

Give an example.

Move the decimal the same number of places in the divisor and dividend until it disappears from the divisor.

2

7 ÷ 5

1.4

3

2.52 ÷ 4

0.63

4

6.3 ÷ 0.3

21

5

15.5 ÷ 0.25

62

Multiply Fractions

1

What do you do when you are multiplying fractions, but one of the factors is a whole number?

Give an example.

Write it over 1.

2

½ × ¼

⅛

3

¹¹⁄₁₂ × ⅖

¹¹⁄₃₀

4

2¼ × ⅘ 

36/20 = 1 16/20 = 1 4/5

Divide Fractions

1

What is a method for dividing fractions.

Give an example.

Zig-Zag or Multiply the Reciprocal (Keep Change Flip)

2

What should you do before you divide mixed numbers ro whole numbers?

Change them to fractions.

3

¾ ÷ ½

6⁄4 = 3⁄2 = 1½

4

1½ ÷ ¾

12⁄6 = 2

5

4½ ÷ ¾

36⁄6 = 6