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MULTIPLYING DECIMALS. EQ: What is the standard algorithm for multiplying decimals? MCC6.NS.3 ---Fluently multiply multi-digit decimals using the standard algorithm. What is a FACTOR? . A number that is multiplied by another number to get a product. What is a PRODUCT? .
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MULTIPLYING DECIMALS EQ: What is the standard algorithm for multiplying decimals? MCC6.NS.3 ---Fluently multiply multi-digit decimals using the standard algorithm.
What is a FACTOR? A number that is multiplied by another number to get a product.
What is a PRODUCT? The ANSWER to a multiplication problem.
When multiplying, is it necessary to line up the decimal points as you do with the addition and subtraction of decimals? It is not necessaryto line up the decimal points when multiplying decimals.
What is the standard algorithm for multiplying decimals? 1) Write down the original problem. 2) Ignore the decimal points and multiply. 3) For each factor, count the total # of places to the right of each decimal point. 4) Use the total number of places right of the decimal point (all factors) for the placement of the decimal point in the product. Start from the last digit in the product and move left.
Let’s try some: 9.65 x 0.88 First Estimate Moving the decimal point 10 1 9.65 0.88 Two to the left plus Two to the left 10 7720 77200 The product will be less than 10 since both estimates are larger than the original factors. 8.4920 Four to the left
5.12 x 0.5 Moving the decimal point First Estimate 5 1 5.12 0.5 two to the left plus one to the left 5 2.560 three to the left The product will be less than 5 because there is a greater increase in the estimate for 0.5 than decrease in the estimate for 5.12
63.7 x 2.9 First Estimate Moving the decimal point 64 3 63.7 2.9 One to the left plus 192 one to the left 5733 12740 The product will be less than 192 because both estimates for the factors are greater. 184.73 two to the left
0.043 x 0.06 First Estimate Moving the decimal point 0 0 0.043 0.06 Three to the left plus Two to the left 0 .00258 Five to the left The product will be less than 1 and closer to 0.
Practice On Your Own 4.37 x 0.39 45.2 x 0.009 7.35 x 8.27 x 1.2
Practice ANSWERS 4.37 x 0.39 = 1.7043 45.2 x 0.009 = 0.4068 7.35 x 8.27 x 1.2 = 72.9414
ASSIGNMENT • Fold paper to make four boxes on each side. This will be your worksheet to turn in for a progressgrade. • Complete problems in Holt math book on page 132 3rd and 6th period: complete problems 33–40 4th and 5th period: complete problems 29–36 • First, copy the original problem on your paper, then solve. Please circle your answers. • When you finish, please turn your work in, put the textbook back, and start on “What did Arf the Dog give his master for his birthday?” (on the table).