1. 01/06/10 Divide Decimals#5 Today’s Plan: -Multiplication Practice -Correct Homework -Divide Decimals Learning Target: -I will divide decimals. Warm Up: 1) 5×7 2) 1×7 3) 4 ×7 4) 9×7 5) 7×10 6) 7×8 7) 7×2 8) 7×3 9) 7×7 10) 7×6 11) 7×100 12) 7×11 LT: I will divide decimals.

2. Timed Test tomorrow 1-7 01/06/10 Divide Decimals#5 Today’s Plan: -Multiplication Practice -Correct Homework -Divide Decimals Learning Target: -I will divide decimals.

3. LT: I will divide decimals. Correct Homework 01/06/10 Divide Decimals#5 Today’s Plan: -Multiplication Practice -Correct Homework -Divide Decimals Learning Target: -I will divide decimals.

4. Divide. Additional Example 1A: Dividing Decimals by Decimals 8.28 ÷ 4.6 ) 82.8 46 1. 46 – 36 8 –36 8 Multiply both numbers by 10. Divide as with whole numbers. 0 Multiply both numbers by the least power of ten that will make the divisor an integer. Helpful Hint A. 8.28 ÷ 4.6 8 = 82.8 ÷ 46 Course 2 4-5 Dividing Decimals and Integers by Decimals

5. Divide. Additional Example 1B: Dividing Decimals by Decimals B. 18.48 ÷ (–1.75) 18.48 ÷ (–1.75) =1848 ÷ 175Multiply both numbers by 100. ) 175 1848. 00 Use zeros as placeholders Divide as with whole numbers. 1 –175 98 0 0.5 –87 5 10 50 –10 50 0 18.48 ÷ (–1.75) = –10.56 6 The signs are different. Course 2 4-5 Dividing Decimals and Integers by Decimals

6. Try This: Example 1A Divide. Insert Lesson Title Here 6.45 ÷ 0.5 ) 64.5 5 1 5 – 14 –10 A. 6.45 ÷ 0.5 2 4 5. 9 –4 5 0 Multiply both numbers by10. Divide as with whole numbers. = 64.5 ÷ 5 Course 2 4-5 Dividing Decimals and Integers by Decimals

7. Divide. B. 16.48 ÷ (–2.06) 16.48 ÷ (–2.06) = 1648 ÷ (206) ) 1,648 206 8 –1 648 16.48 ÷ (–2.06) = –8 Multiply both numbers by 100. Divide as with whole numbers. 0 Try This: Example 1B The signs are different. Course 2 4-5 Dividing Decimals and Integers by Decimals

8. Divide. Estimate to check whether the answer is reasonable. Additional Example 2A: Dividing Integers by Decimals A. 4 ÷ 1.25 4.00 ÷ 1.25 = 400 ÷ 125 Multiply both numbers by 100. ) 125 400.0.0 Use zero as a placeholder. 3 –375 25 0 –25 0 0 Divide as with whole numbers. Estimate 4 ÷ 1 = 4 The answer is reasonable.. 2 Course 2 4-5 Dividing Decimals and Integers by Decimals

9. Divide. Estimate to check whether the answer is Reasonable. Additional Example 2B: Dividing Integers by Decimals B. –24 ÷ (–2.5) –24.0 ÷ (–2.5) = Multiply both numbers by 10. –240 ÷ (–25) ) 25 240 9 – 225 15.. 0 0 6 – 15 0 0 Estimate –24 ÷ (–3) = 8 The answer is reasonable. Divide as with whole numbers. Course 2 4-5 Dividing Decimals and Integers by Decimals

10. Divide. Estimate to check whether the answer is reasonable. Try This: Example 2A A. 6 ÷ 1.25 6.00 ÷ 1.25 = 600 ÷ 125 Multiply both numbers by 100. ) 125 600.0.0 Use zero as a placeholder. 4 –500 100 0 –100 0 0 Divide as with whole numbers. Estimate 6 ÷ 1 = 6 The answer is reasonable.. 8 Course 2 4-5 Dividing Decimals and Integers by Decimals

11. Divide. Estimate to check whether the answer is Reasonable. Try This: Example 2B B. –22 ÷ (–2.5) –22.0 ÷ (–2.5) = Multiply both numbers by 10. –220 ÷ (–25) ) 25 220 8 –200 20.. 0 0 8 –20 0 0 Estimate –22 ÷ (–3) = 7 The answer is reasonable. Divide as with whole numbers. Course 2 4-5 Dividing Decimals and Integers by Decimals

12. You can buy juice by the bottle or case. Either way, it costs the same for each bottle. A case of 24 bottles of juice cost $23.52. Kevin bought a bag of peanuts for 75¢ and one bottle of juice. How much did Kevin spend in all? Additional Example 2: Money Application Course 2 4-4 Dividing Decimals by Integers First find the cost for one bottle of juice by dividing the cost of a case by the number of bottles in a case. Then add the cost of a bag of peanuts. 0 ) 24 23.52 21 6 1 92 –1 92 0 $0.98 + $0.75 = $1.73 Kevin spent a total of $1.73.98 Place the decimal point for the answer directly above the decimal under the division symbol. One bottle of juice costs $0.98 and a bag of peanuts costs $0.75

13. Try This: Example 2 Insert Lesson Title Here Course 2 4-4 Dividing Decimals by Integers 0 ) 12 1.80 1 2 60 – 60 0 $1.79 + $0.15 = $1.94 John spent a total of $1.94..1 5 Place the decimal point for the answer directly above the decimal under the division symbol. Cookies at a store sell for $1.80 a dozen. The cost for each cookie is the same whether you buy them individually or by the dozen. John decided to buy 1 cookie and a quart of milk. The milk cost $1.79. How much did John have to pay? First find the cost of one cookie by dividing the cost of a dozen by 12. Then add the price for the milk. One quart of milk costs $1.79 and one cookie costs $0.15.

14. Division Vocabulary The dividend is the number that is being divided. The divisor is the number that the dividend will be divided by. The quotient is the number of times the divisor will go into the dividend. (The answer to the division problem.) dividend ÷ divisor = quotient or quotient divisor ) dividend In this example 5 is the divisor, 36 is the dividend, 7.2 is the quotient. – 35 ) 536.0 7.2 10 – 10 0 36 ÷ 5 = 7.2

15. LT: I will divide decimals. Page 212 #1-6 01/06/10 Divide Decimals#5 Today’s Plan: -Multiplication Practice -Correct Homework -Divide Decimals Learning Target: -I will divide decimals.