Operations on Rational Numbers in Decimal Form

Operations on Rational Numbers in Decimal Form

Addition and Subtraction

• Align the decimal points

• Add/subtract from the smallest place value (from the right)

• Follow the rule of signs of integers

Practice

5 items

Multiple Choice

12.8-5.3=

• 6.5

• 7.5

• 8.5

• 9.5

Multiple Choice

-40.5+55.5=

• 5

• 10

• 15

• 20

Multiple Choice

Evaluate the sum of -2.3 and -4.5

• 6.8

• 2.2

• -6.8

• -2.2

Multiple Choice

0.1 + 0.01=

• 0.02

• 0.11

• 1.11

• 0.2

Multiple Choice

Solve.

3.9 + (-2.2) =

• -6.1

• 6.1

• 1.7

• -1.7

Multiplication

• Align the numbers on the right.

• Multiply normally.

• The number of decimal places of the product is the SUM of the decimal places of the factors.

• Follow the rule of sign of integers

Practice

3 items

Multiple Choice

0.23 (-5.4)

• -12.42

• 1.242

• 12.42

• -1.242

Multiple Choice

(-0.35)(-6)

• 210

• 21

• 2.1

• 0.21

Multiple Choice

(-4.5)( 6.2)

• 27.9

• -2.79

• -27.9

• 2.79

Division

• Make the divisor a whole number by multiplying a power of 10. Multiply this power of 10 to the dividend, too.

• Divide normally.

• Follow the rule of sign of integers.

Practice

4 items

Multiple Choice

Find an equivalent expression to 0.85 ÷ 0.5

• 8.5 ÷ 5

• 85 ÷ 5

• 0.85 ÷ 5

• 850 ÷ 50

Multiple Choice

What is 1954 ÷ 10?

• 1954

• 195.4

• 19540

• 19.54

Multiple Choice

Divide:

-3.6 ÷ (-0.6)

• 6

• 60

• 600

• .6

Multiple Choice

-0.35 ÷ 0.7

• -0.05

• -0.5

• 0.05

• 0.5