MATH

1. DECIMALS
Rounding Decimals Review
and
Multiplying Decimals

2. ___ , ___ ___ ___ ___ ___ ___ ___
Thousands
Hundreds
Tens
Ones
Tenths
Hundredths
Thousandths
Ten
Thousandths
5 1 8 2 1
Read as 518 and 21 hundredths
Decimals are read as “and”
Review

3. Steps for Multiplying Decimals
Step 1: Write the problem vertically.
Step 2: Ignore the decimal point(s) and multiply.
Step 3: Determine where the decimal point
goes in the product.
Place the decimal point in the answer
by counting how many places the
decimal point has moved.
Multiplying Decimals

4. Multiply 3 x 0.14
0.14 3 x 0.14
=
0.42
Multiplying Decimals

5. Multiply 3 x 0.14
2
Step 1: Write the problem vertically
0.14
x 3 Step 2: Ignore the decimal points
and multiply
Step 3: Determine where the decimal
point goes in the product.
The decimal moves two places to the left
1
4
0
0.42
Multiplying Decimals

6. Multiply 5 x 0.18
0.18 5 x 0.18
=
0.90
Multiplying Decimals

7. Multiply 5 x 0.18
0
Step 1: Write the problem vertically
0.18
x 5 Step 2: Ignore the decimal points
and multiply
Step 3: Determine where the decimal
point goes in the product.
The decimal moves two places to the left
4
9
0
0.90
Multiplying Decimals

8. Multiply 0.2 x 0.6
0.2 0.6
=
0.2
Multiplying Decimals

9. Multiply 0.2 x 0.6
0.2 0.6
=
0.2 x 0.6
Multiplying Decimals

10. Multiply 0.2 x 0.6
0.2 0.6
=
0.2 x 0.6
= 0.12
Multiplying Decimals

11. Multiply 0.2 x 0.6
2
Step 1: Write the problem vertically
0.2
x 0.6 Step 2: Ignore the decimal points
and multiply
Step 3: Determine where the decimal
point goes in the product.
The decimal moves two places to the left
1
0
0. 12
Multiplying Decimals

12. Multiply 0.4 x 0.7
0.4 0.7
=
0.4
Multiplying Decimals

13. Multiply 0.4 x 0.7
0.4 0.7
=
0.4 x 0.7
Multiplying Decimals

14. Multiply 0.4 x 0.7
0.4 0.7
=
0.28
Multiplying Decimals

15. Multiply 0.4 x 0.7
8
Step 1: Write the problem vertically
0.4
x 0.7 Step 2: Ignore the decimal points
and multiply
Step 3: Determine where the decimal
point goes in the product.
The decimal moves two places to the left
2
0
0. 28
Multiplying Decimals

16. Multiplying Decimals
200
x .25
0
+
5000
0
0
0
1
0
0
4
Move the
decimal
two places
to the left in
your answer.
.

17. Multiplying Decimals
HOW MANY DECIMAL PLACES?
1 decimal place
3.1
2) (0.4)(2.53)
0.4
 2.53
1) 3.1(0.28)
1.012
 0.28 2 decimal places
0.868 1 + 2 = 3 decimal places
1 decimal place
2 decimal places
1 + 2 = 3 decimal places

18. Multiplying Decimals
1) 0.16
x 30
0
0
0
0
8
4
0
8
4
1
2) 70
x 1.2
0
4
1
0
0
7
0
4
8
+
3)
1
0.0048
x 32
6
9
0
0
4
4
6
3
5
1
1
1
2
0
0
1
0