Student Progress Chart

1. Student Progress Chart Lesson Reflection 3-6

2. Math Learning GoalStudents will understand decimals.

3. Students will understand decimals by being able to do the following: • Learn to write, compare, and order decimals using place value and number lines (3-1) • Learn to estimate decimal sums, differences, products, and quotients (3-2) • Learn to add and subtract decimals (3-3) • Learn to multiply and divide decimals by powers of ten and to convert metric measurements (3-4) • Learn to write large numbers in scientific notation (3-5) • Learn to multiply decimals by whole numbers and by decimals (3-6)

4. 3-6 Multiplying Decimals Course 1 Today’s Learning Goal Assignment Learn to multiply decimals by whole numbers and by decimals.

5. 3-6 Multiplying Decimals Course 1 6th Grade Math HW Page 122 #10-25

6. 3-6 Multiplying Decimals Course 1 Warm Up Problem of the Day Lesson Presentation

7. 3-6 Multiplying Decimals Course 1 Warm Up Multiply. 1.87  320 27,840 2. 943  800 754,400 3. 3,806  10 38,060 4. 1,207  100 120,700 5. 72  196 14,112 6. 120  523 62,760

8. 3-6 Multiplying Decimals Course 1 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

9. 3-6 Multiplying Decimals Course 1 Today’s Learning Goal Assignment Learn to multiply decimals by whole numbers and by decimals.

10. 3-6 Multiplying Decimals You can think of multiplication by a whole number as a repeated addition. Course 1 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? 4  0.17 0.17 0.17 0.17 0.17 + _____ 0.68

11. 3-6 Multiplying Decimals You can also multiply as you would with whole numbers. Place the decimal point by adding the number of decimal places in the numbers multiplied. 2 decimal places + 0 decimal places 2 decimal places Course 1 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? 0.17 4  _____ 0.68 A 4 lb dumbbell on Earth weighs 0.68 lb on the Moon.

12. 3-6 Multiplying Decimals You can think of multiplication by a whole number as a repeated addition. Course 1 Try This: 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? 7  0.17 0.17 0.17 0.17 0.17 0.17 0.17 0.17 + _____ 1.19

13. 3-6 Multiplying Decimals You can also multiply as you would with whole numbers. Place the decimal point by adding the number of decimal places in the numbers multiplied. 2 decimal places + 0 decimal places 2 decimal places Course 1 Try This: 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? 0.17 7  _____ 1.19 A 7 lb dumbbell on Earth weighs 1.19 lb on the Moon.

14. 3-6 Multiplying Decimals Multiply. Then place the decimal point. 1 decimal place + 1 decimal place 2 decimal places Course 1 Additional Example 2A: Multiplying a Decimal by a Decimal Find the product. A. 0.3  0.4 0.3  0.4 0.12

15. 3-6 Multiplying Decimals Multiply. Then place the decimal point. 2 decimal places + 1 decimal place 3 decimal places; use a placeholder zero Estimate the product. 0.8 is close to 1. Course 1 Additional Example 2B: Multiplying a Decimal by a Decimal B. 0.07  0.8 0.07  1 = 0.07 0.07 0.8  0.056 0.056 is close to the estimate of 0.07. The answer is reasonable.

16. 3-6 Multiplying Decimals 2 decimal places Estimate the product. Round each factor to the nearest whole number. Multiply. Then place the decimal point. 3 decimal places + 1 decimal place Course 1 Additional Example 2C: Multiplying a Decimal by a Decimal C. 1.34  2.5 1  3 = 3 1.34  2.5 670 2680 3.350 3.350 is close to the estimate of 3. The answer is reasonable.

17. 3-6 Multiplying Decimals Multiply. Then place the decimal point. 1 decimal place + 1 decimal place 2 decimal places Course 1 Try This: Example 2A Find each product. A. 0.5  0.2 0.5  0.2 0.10

18. 3-6 Multiplying Decimals Multiply. Then place the decimal point. 2 decimal places + 1 decimal place 3 decimal places; use a placeholder zero Estimate the product. 0.9 is close to 1. Course 1 Try This: Example 2B B. 0.03  0.9 0.03  1 = 0.03 0.03 0.9  0.027 0.027 is close to the estimate of 0.03. The answer is reasonable.

19. 3-6 Multiplying Decimals 2 decimal places Estimate the product. Round each factor to the nearest whole number. Multiply. Then place the decimal point. 3 decimal places + 1 decimal places Course 1 Try This: Example 2C C. 3.80  3.3 4  3 = 12 3.80  3.3 1140 11400 12.540 12.54 is close to the estimate of 12. The answer is reasonable.

20. 3-6 Multiplying Decimals Remember! These notations all mean multiply 3 times x. 3 •x 3x 3(x) 3 decimal places + 0 decimal places 3 decimal places Substitute 3.062 for x. Course 1 Additional Example 3A: Evaluating Decimal Expressions Evaluate 5x for each value of x. A. x = 3.062 5x = 5(3.062) 3.062  5 15.310

21. 3-6 Multiplying Decimals 2 decimal places + 0 decimal places 2 decimal places Substitute 4.79 for x. Course 1 Additional Example 3B: Evaluating Decimal Expressions B. x = 4.79 5x = 5(4.79) 4.79 5  23.95

22. 3-6 Multiplying Decimals 3 decimal places + 0 decimal places 3 decimal places Substitute 2.012 for x. Course 1 Try This: Example 3A Evaluate 5x for each value of x. A. x = 2.012 5x = 5(2.012) 2.012 5  10.060

23. 3-6 Multiplying Decimals 2 decimal places + 0 decimal places 2 decimal places Substitute 6.22 for x. Course 1 Try This: Example 3B B. x = 6.22 5x = 5(6.22) 6.22  5 31.10

24. 3-6 Multiplying Decimals Course 1 Insert Lesson Title Here Lesson Quiz Find each product. 1. 0.8 2. 0.006  0.07 Evaluate 8x for each value of x.  0.07 0.056 0.00042 3.x = 2.705 4.x = 0.804 6.432 21.64 5. “Pick your own” peaches sell for $0.95 per pound. You picked 92 pounds of peaches. How much were you charged? $87.40