Download presentation

Presentation is loading. Please wait.

Published byStephanie Warner Modified over 6 years ago

1
**3-5 Multiplying Decimals Warm Up Problem of the Day**

Course 1 Warm Up Problem of the Day Lesson Presentation

2
**3-5 Multiplying Decimals Warm Up Multiply. 1. 87 320 27,840**

Course 1 3-5 Multiplying Decimals Warm Up Multiply. 1. 87 320 27,840 800 754,400 3. 3,806 10 38,060 4. 1,207 100 120,700 5. 72 196 14,112 523 62,760

3
**3-5 Multiplying Decimals Problem of the Day**

Course 1 3-5 Multiplying Decimals Problem of the Day Carmen and Rita sold homemade oatmeal cookies. After 8 days, they had sales totaling $70. Each day, their sales were $0.50 higher than the previous day. What were their sales on the first day? $7.00

4
**3-5 Multiplying Decimals**

Course 1 3-5 Multiplying Decimals Learn to multiply decimals by whole numbers and by decimals.

5
**Additional Example 1: Science Application**

Course 1 3-5 Multiplying Decimals Additional Example 1: 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. 4 0.17 17 Multiply as you would with whole numbers. 4 68

6
**Additional Example 1 Continued**

Course 1 3-5 Multiplying Decimals Additional Example 1 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? Place the decimal point by adding the number of decimal places in the numbers multiplied. 0.17 2 decimal places 4 + 0 decimal places 0.68 2 decimal places A 4 lb dumbbell on Earth weighs 0.68 lb on the Moon.

7
**3-5 Multiplying Decimals 7 Check It Out: Example 1**

Course 1 3-5 Multiplying Decimals Check It Out: Example 1 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? Multiply 7 by 0.17, since 1 pound on Earth is 0.17 pound on the Moon. 7 0.17 17 Multiply as you would with whole numbers. 7 119

8
**Check It Out: Example 1 Continued**

Course 1 3-5 Multiplying Decimals Check It Out: Example 1 Continued 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? Place the decimal point by adding the number of decimal places in the numbers multiplied. 0.17 2 decimal places 7 + 0 decimal places 1.19 2 decimal places A 7 lb dumbbell on Earth weighs 1.19 lb on the Moon.

9
**3-5 Multiplying Decimals Helpful Hint**

Course 1 3-5 Multiplying Decimals You can use a decimal grid to model multiplication of decimals. Helpful Hint

10
**Additional Example 2A: Multiplying a Decimal by a Decimal**

Course 1 3-5 Multiplying Decimals Additional Example 2A: Multiplying a Decimal by a Decimal Find the product. 0.3 0.4 Multiply. Then place the decimal point. 1 decimal place 0.3 + 1 decimal place 0.4 2 decimal places 0.12

11
**Additional Example 2B: Multiplying a Decimal by a Decimal**

Course 1 3-5 Multiplying Decimals Additional Example 2B: Multiplying a Decimal by a Decimal 0.07 0.8 Estimate the product. 0.8 is close to 1. 0.07 1 = 0.07 Multiply. Then place the decimal point. 2 decimal places 0.07 0.8 + 1 decimal place 3 decimal places; use a placeholder zero 0.056 0.056 is close to the estimate of The answer is reasonable.

12
**Additional Example 2C: Multiplying a Decimal by a Decimal**

Course 1 3-5 Multiplying Decimals Additional Example 2C: Multiplying a Decimal by a Decimal 1.34 2.5 Estimate the product. Round each factor to the nearest whole number. 1 3 = 3 Multiply. Then place the decimal point. 1.34 2.5 2 decimal places 670 + 1 decimal place 2680 3 decimal places 3.350 3.350 is close to the estimate of 3. The answer is reasonable.

13
**3-5 Multiplying Decimals Check It Out: Example 2A Find the product.**

Course 1 3-5 Multiplying Decimals Check It Out: Example 2A Find the product. 0.5 0.2 Multiply. Then place the decimal point. 1 decimal place 0.5 + 1 decimal place 0.2 2 decimal places 0.10

14
**3-5 Multiplying Decimals Check It Out: Example 2B 0.03 0.9**

Course 1 3-5 Multiplying Decimals Check It Out: Example 2B 0.03 0.9 Estimate the product. 0.9 is close to 1. 0.03 1 = 0.03 Multiply. Then place the decimal point. 0.03 2 decimal places 0.9 + 1 decimal place 0.027 3 decimal places; use a placeholder zero 0.027 is close to the estimate of The answer is reasonable.

15
**3-5 Multiplying Decimals Check It Out: Example 2C 3.80 3.3**

Course 1 3-5 Multiplying Decimals Check It Out: Example 2C 3.80 3.3 Estimate the product. Round each factor to the nearest whole number. 4 3 = 12 Multiply. Then place the decimal point. 3.80 3.3 2 decimal places 1140 + 1 decimal places 11400 3 decimal places 12.540 12.54 is close to the estimate of 12. The answer is reasonable.

16
**Additional Example 3A: Evaluating Decimal Expressions**

Course 1 3-5 Multiplying Decimals Additional Example 3A: Evaluating Decimal Expressions Evaluate 5x for the value of x. x = 3.062 Substitute for x. 5x = 5(3.062) 3 decimal places 3.062 5 + 0 decimal places 15.310 3 decimal places These notations all mean multiply 3 times x. 3 • x 3x 3(x) Remember!

17
**Additional Example 3B: Evaluating Decimal Expressions**

Course 1 3-5 Multiplying Decimals Additional Example 3B: Evaluating Decimal Expressions Evaluate 5x for the value of x. x = 4.79 Substitute 4.79 for x. 5x = 5(4.79) 2 decimal places 4.79 5 + 0 decimal places 23.95 2 decimal places

18
**3-5 Multiplying Decimals Check It Out: Example 3A**

Course 1 3-5 Multiplying Decimals Check It Out: Example 3A Evaluate 5x for the value of x. x = 2.012 Substitute for x. 5x = 5(2.012) 3 decimal places 2.012 5 + 0 decimal places 10.060 3 decimal places

19
**3-5 Multiplying Decimals Check It Out: Example 3B**

Course 1 3-5 Multiplying Decimals Check It Out: Example 3B Evaluate 5x for the value of x. x = 6.22 Substitute 6.22 for x. 5x = 5(6.22) 2 decimal places 6.22 5 + 0 decimal places 31.10 2 decimal places

20
**Insert Lesson Title Here**

Course 1 3-5 Multiplying Decimals Insert Lesson Title Here Lesson Quiz Find each product. 0.07 Evaluate 8x for each value of x. 0.07 0.056 3. x = x = 0.804 21.64 6.432 5. “Pick your own” peaches sell for $0.95 per pound. You picked 92 pounds of peaches. How much were you charged? $87.40

Similar presentations

© 2022 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google