Multiplying and Adding Decimals

Multiplying and Adding Decimals

Let's Review our Rules :)

Poll

When Adding or subtracting decimals you....

• line up the decimals and add and subtract like normal

• do not line up your decimals (aka - move the decimal point at the end)

Adding & Subtracting Rules

Line Up Your Decimal!!

What about adding (or subtracting) a decimal with a whole number???

Turn & Talk: What do we do?

Poll

When multiplying decimals you...

• line up the decimals and multiply like normal

• do not line up the decimals (move them to the side and move them back over at the end) and multiply like normal

If both numbers have a decimal...

Count the number of place values after the decimal for EACH number. When you get to your answer, move the decimal back that many places.

Multiple Choice

21 + 4.09 =

• 4.30
• 6.19
• 25.09
• 16.91

Multiple Choice

7.8 + 1.34 =

• 9.14

• 2.12

• 6.46

• 8.42

Multiple Choice

18.7 x 6 = _

• 112.2

• 11.22

• 112.1

• 1.121

Multiple Choice

81.9 x 0.5 =

• 40.95

• 409.5

• 40.02

• 400.2