2. New Vocabulary VocabularyDefinitionUsing symbols productThe answer to a multiplication problem 2 x 4 = 8 product Multiplying Decimals

4. Example: Science Application Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 4 lb dumbbell weigh on the Moon? Multiply 4 by 0.17, since 1 pound on Earth is 0.17 pound on the Moon. 17  4 68 Multiply as you would with whole numbers. 4  0.17 Multiplying Decimals

5. Example Continued Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 4 lb dumbbell weigh on the Moon? 0.17  4 0.68 Place the decimal point by adding the number of decimal places in the numbers multiplied. A 4 lb dumbbell on Earth weighs 0.68 lb on the Moon. 2 decimal places + 0 decimal places 2 decimal places Multiplying Decimals

6. Check It Out Something that weighs 1 lb on Earth weighs 0.17 lb on the Moon. How much would a 7 lb dumbbell weigh on the Moon? 7 × 0.17 = 1.19 lb Multiplying Decimals

7. You can use a decimal grid to model multiplication of decimals. Helpful Hint Multiplying Decimals

8. Example: Multiplying a Decimal by a Decimal Find the product. 0.3  0.4 Multiply. Then place the decimal point. 0.3 0.4  1 decimal place + 1 decimal place2 decimal places 0.12 Multiplying Decimals

9. Example: Multiplying a Decimal by a Decimal 0.07  0.8 Multiply. Then place the decimal point. 0.07  0.8 2 decimal places + 1 decimal place3 decimal places; use a placeholder zero 0.056 Estimate the product. 0.8 is close to 1. 0.07  1 = 0.07 0.056 is close to the estimate of 0.07. The answer is reasonable. Multiplying Decimals

10. Example: Multiplying a Decimal by a Decimal 1.34  2.5 Multiply. Then place the decimal point. 1.34 2.5  2 decimal places + 1 decimal place3 decimal places 670 Estimate the product. Round each factor to the nearest whole number. 1  3 = 3 3.350 is close to the estimate of 3. The answer is reasonable. 2680 3.350 Multiplying Decimals

11. Check It Out Find the product. 3.80 × 3.3 3.80 3.3  1140 11400 12.540 = 12.54 Multiplying Decimals

12. 1. Identify the product. 0.29  0.01 A. 0.29 B. 0.029 C. 0.0029 D. 0.00029 Student Response Systems Multiplying Decimals

13. 5. Strawberry lemonade costs $0.89 per packet. Karen bought 58 packets of strawberry lemonade for a picnic. How much did she pay for it? A. $51.62 B. $51.86 C. $52.54 D. $52.93 Student Response Systems Multiplying Decimals