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Activator. Multiply 23 x 18. Multiply .23 x 1.8 What is the same about both answers? They have the same digits? 414. Multiplying and Dividing Decimals. Step 1: You do not have to line the decimals up when multiplying. 2.36 * 5 Step 2: Multiply as normal. 2.36

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  1. Activator Multiply 23 x 18. Multiply .23 x 1.8 What is the same about both answers? They have the same digits? 414

  2. Multiplying and Dividing Decimals Step 1: You do not have to line the decimals up when multiplying. 2.36 * 5 Step 2: Multiply as normal. 2.36 * 5 The decimal in the product has the same number of digits behind it as the total number of digits behind decimals in the factors.

  3. Tell how many digits will be behind the decimal in the answer for numbers 5-8. Do not solve: 1 3 2 2

  4. Multiplying and Dividing Decimals • Practice Problems: • 8 * 1.11 • 3.26 * 123

  5. Assessment Prompt • Do decimals have to line up when multiplying them? • Thumbs up yes or Thumbs down no • Thumbs down: you do not need to line up the decimals. If you do you can still get the correct answer but you don’t need to.

  6. Dividing with Decimals Dividing decimals by whole numbers Dividing decimals by decimals (the divisor must be turned into a whole #)

  7. Dividing Decimals Dividing Decimals by whole numbers Step 1: Set up the problem and then bring the decimal straight up into the quotient. Step 2: Divide as normal.

  8. Dividing Decimals • Do not copy: just read • Step 3: For use with a whole number dividend: When you get to the remainder add a decimal in the dividend and quotient. Use zeros as place holders. Keep dividing Copy this only: If dividend is a whole number you may need to add a decimal and zeros to keep going. Copy example

  9. EXAMPLE 1 Dividing a Decimal by a Whole Number Soccer – Your soccer team orders sports cards for each player. You buy a set of 8 cards for $9.92. How much do you pay for each card? To answer the question above about sports cards, Find 9.92 ÷ 8. Just click through the next several sides. The 8 is the divisor so all you do is set up the problem and move the decimal straight up.

  10. ) EXAMPLE 1 Dividing a Decimal by a Whole Number To answer the question above about sports cards, STEP 1 Place the decimal point. . 9.92 8

  11. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 8 9.92

  12. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1 8 9.92 8

  13. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1 8 9.92 8 1

  14. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1 8 9.92 8 1 9

  15. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.2 8 9.92 8 1 9 1 6

  16. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.2 8 9.92 8 1 9 1 6 3

  17. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.2 8 9.92 8 1 9 1 6 32

  18. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.24 8 9.92 8 1 9 1 6 32 32

  19. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.24 8 9.92 8 1 9 1 6 32 32 0

  20. ) EXAMPLE 1 Dividing a Decimal by a Whole Number STEP 2 Then divide. 1.24 8 9.92 8 1 9 1 6 32 32 0 ANSWER You pay $1.24 for each sports card.

  21. Dividing Decimals • Step 1: Dividing decimals by decimals: Turn the divisor into a whole number. • Step 2: Move the decimal in the dividendto the right the same number of places you moved in the divisor.

  22. Dividing Decimals • Step 3: Bring the decimal straight up. • Step 4:Dividelikenormal.

  23. Stop!! • Homework Assignment: • Put in tracker. Textbook pg.8 #1-6. They gave you the problems and answers. Your job is to put the decimal in the right spot. • Textbook pg. 9. #8, 11, 14, 17. Do not solve. Just tell me how many numbers will be behind the decimal in the answer. • Example: 1.23 x .4 = 3 decimal places.

  24. Activator • Pair share what you remember about dividing with decimals from yesterday.

  25. EXAMPLE 1 Writing Divisors as Whole Numbers Rewrite the division problem so that the divisor is a whole number. a. 1.83 2.5

  26. EXAMPLE 1 Writing Divisors as Whole Numbers Rewrite the division problem so that the divisor is a whole number. a. 1.83 2.5 ) 1.83 2.5

  27. EXAMPLE 1 Writing Divisors as Whole Numbers Rewrite the division problem so that the divisor is a whole number. a. 1.83 2.5 Multiply the divisor and dividend by 10. ) 1.83 2.5

  28. EXAMPLE 1 Writing Divisors as Whole Numbers Rewrite the division problem so that the divisor is a whole number. a. 1.83 2.5 Multiply the divisor and dividend by 10. ) 1.83 2.5 ANSWER 18.3 25

  29. Assessment Prompt • If you have to change the divisor from a decimal to a whole #, what else must you do? • Will the dividend always become a whole number? • In this problem identify the divisor and dividend. 14.278 ÷ 5.01

  30. Changing so divisor is a whole number • Change the following problems so the divisor is a whole number. • 15.278 ÷ 0.21 0.368 ÷ 0.2

  31. Pair Share • Using your dominos, you and a partner will create an addition, subtraction, multiplication, and division problem.

  32. Textbook pg. 12 • #1-12. • You are going to rewrite each problem so that the divisor is a whole number. • Remember rules about changing numbers in a problem. • #7-12 you are going to also write what you would multiply the divisor by to make it a whole number.

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