1. Decimals

2. Place Value Review - *Whole*
9,587,541,645,315
trillions
hundred billions
ten billions
billions
hundred millions
ten millions
millions
hundred thousands
ten thousands
thousands
hundreds
tens
ones
Each position is 10 times bigger than the last!

3. Decimal Place Value – *Parts*
DECIMAL POINT
tenths
hundredths
thousandths
ten thousandths
hundred thousandths
millionths
ten millionths
hundred millionths
billionths
ten billionths
hundred billionths
trillionths
Each position gets 10 times smaller!

4. Decimal Place Value Chart

5. Types of Decimals Terminating Decimal- a decimal that ends
ex:
Repeating Decimal- a decimal that continues on
forever with one or more digits repeating a pattern
ex: … … …
aka aka aka 5.09

6. Rounding Decimals
1. Find the place value you want to round to (the “rounding digit”)
If the number to the right of “the rounding digit” is less than 5,
make all numbers to the right of the rounding digit zeros
If the number is greater than 5, add one to the rounding digit
and then everything to the right becomes zero
ex: Round to the nearest hundredth 8
1. Find hundredth
2. Is the number to the right bigger than 5?
3. Yes. Then Round 8 up to 9 and the following numbers go away
54.99
Is the answer

7. Adding & Subtracting Decimals
Line up the decimal points and add or subtract.
5.02
ADD ex . 11 3 4 5 12
SUBTRACT ex
12.45
- _7.3_ / / . 5 1 5

8. iPad Activity – Adding Decimals

9. Use Distributive Property to solve mentally!
Multiply Decimals
Ignore the decimal point
Multiply the whole numbers as you normally would.
ex • 5.3
6 • 53
_____ ____
6 • • 3
318
Use Distributive Property to solve mentally!
3. Count how many decimal places you started with
4. Keep that same number of decimal places in the answer
ex •
One decimal place
One decimal place

10. Multiply Decimals Practice
236
x 25
1180
+4720
5900
ex x
5900 .
2 places
4 places
6 places
.0059

11. More Multiplication Practice
5 x 0.25
3 x 1.4
8 x 5.1
3.20 x 7
5.33 x 6.2
1.25
4.2
40.8
22.4
33.046

12. Divide Decimals by whole numbers
ex ÷5 . 5
16.25
1. Use long division
2. Bring decimal point up into the answer. .
3. Solve 3 2 5 5
16.25
3.25 15 1 2 10 2 5 25

13. Divide Decimals by decimals
ex ÷ 6.2
6.2
18.6
1. Use long division
2. Make the divisor a whole number
6.2
62.
3. Move dividend decimal the same number of spaces
18.6
186.
4. Solve using long division 3 . 3
62.
186.
186
5. Bring decimal point up into the answer.

14. Decimal means “Based on 10”
After every whole number, there is a decimal point.
ex. 5
5.0 or or etc. But it all means “5”
Multiply by 10: the decimal point moves right, making the number larger.
ex • = = 120
ex • =
Divide by 10: the decimal point moves left, making the number smaller.
ex ÷ = = 1.2
ex ÷ =