1. 3-5 Dividing Decimals by Whole Numbers Homework Presentation Homework Presentation

2. 3-5 Dividing Decimals by Whole Numbers Learn to divide decimals by whole numbers.

3. 3-5 Dividing Decimals by Whole Numbers Divisor Quotient Remember! 0.15 0.75 5 Dividend

4. 3-5 Dividing Decimals by Whole Numbers Additional Example 1A: Dividing a Decimal by a Whole Number Find the quotient. 0.84 ÷ 3 3 0.84 – 6 24 – 24 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. 0.28

5. 3-5 Dividing Decimals by Whole Numbers Additional Example 1B: Dividing a Decimal by a Whole Number Find the quotient. 3.56 ÷ 4 4 3.56 – 32 36 – 36 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. 0. 89

6. 3-5 Dividing Decimals by Whole Numbers Check It Out: Example 1A Find the quotient. 0.72 ÷ 3 3 0.72 – 6 12 – 12 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. 0.24

7. 3-5 Dividing Decimals by Whole Numbers Check It Out: Example 1B Find the quotient. 2.96 ÷ 4 4 2.96 – 28 16 – 16 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. 0. 74

8. 3-5 Dividing Decimals by Whole Numbers Additional Example 2A: Evaluating Decimal Expressions Evaluate 0.936 ÷ x for the given value of x. x = 9 9 0.936 – 9 3 – 0 36 Substitute 9 for x. 0.10 0.936 ÷ x 0.936 ÷ 9 – 36 0 4 Sometimes you need to use a zero as a placeholder. 9 > 3, so place a zero in the quotient and divide 9 into 36.

9. 3-5 Dividing Decimals by Whole Numbers Additional Example 2B: Evaluating Decimal Expressions Evaluate 0.936 ÷ x for the given value of x. x = 18 18 0.936 – 0 93 – 90 36 Substitute 18 for x. 0.05 0.936 ÷ x 0.936 ÷ 18 – 36 0 2 Sometimes you need to use a zero as a placeholder. 18 > 9, so place a zero in the quotient and divide 18 into 93.

10. 3-5 Dividing Decimals by Whole Numbers Check It Out: Example 2A Evaluate 0.636 ÷ x for the given value of x. x = 6 6 0.636 – 6 3 – 0 36 Substitute 6 for x. 0.10 0.636 ÷ x 0.636 ÷ 6 – 36 0 6 Sometimes you need to use a zero as a placeholder. 6 > 3, so place a zero in the quotient and divide 6 into 36.

11. 3-5 Dividing Decimals by Whole Numbers Check It Out: Example 2B Evaluate 0.636 ÷ x for the given value of x. x = 12 12 0.636 – 0 63 – 60 36 Substitute 12 for x. 0.05 0.636 ÷ x 0.636 ÷ 12 – 36 0 3 Sometimes you need to use a zero as a placeholder. 12 > 6, so place a zero in the quotient and divide 12 into 63.

12. 3-5 Dividing Decimals by Whole Numbers Multiplication can “undo” division. To check your answer to a division problem, multiply the divisor by the quotient. Remember!

13. 3-5 Dividing Decimals by Whole Numbers Additional Example 3: Consumer Application Jodi and three of her friends are making a tile design. The materials cost $10.12. If they share the cost equally, how much should each person pay? 4 $10.12 – 8 21 – 20 12 $2. 53 $10.12 should be divided into four equal groups. Divide $10.12 by 4. – 12 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. Check 2.53  4 = 10.12 Each person should pay $2.53.

14. 3-5 Dividing Decimals by Whole Numbers Check It Out: Example 3 Ty and three of his friends are building a fence. The lumber costs $21.44. If they share the cost equally, how much should each person pay? 4 $21.44 – 20 14 – 12 24 $5.36 $21.44 should be divided into four equal groups. Divide $21.44 by 4. – 24 0 Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers. Check 5.36  4 = 21.44 Each person should pay $5.36.

15. 3-5 Dividing Decimals by Whole Numbers Check For Understanding Find each quotient. 1. 3.12 ÷ 82. 5.68 ÷ 8 Evaluate the expression 1.25 ÷ x for the given value of x. 3. x = 54. x = 25 5. The tennis team is having 3 of their tennis rackets restrung. The total cost is $54.75. What is the average cost per racket?