The document discusses multiplying decimals. It provides steps for multiplying decimals which include writing the problem vertically, ignoring the decimal points and multiplying, then determining where to place the decimal point in the product based on how many places the decimal point moved. Several examples are shown of multiplying decimals with explanations of applying the steps. The document also discusses determining the number of decimal places in a product of decimals.

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