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 necessary to 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 First Estimate The product will be less than 10 since both estimates are larger than the original factors. Two to the left Four to the left plus Moving the decimal point

5.12 x First Estimate 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 two to the left one to the left three to the left plus Moving the decimal point

63.7 x First Estimate The product will be less than 192 because both estimates for the factors are greater. One to the left one to the left two to the left plus Moving the decimal point

0.043 x First Estimate 0 0 The product will be less than 1 and closer to 0. Three to the left Two to the left Five to the left plus Moving the decimal point

Practice On Your Own 4.37 x x x 8.27 x 1.2

Practice ANSWERS 4.37 x 0.39 = x = x 8.27 x 1.2 =

ASSIGNMENT O Fold paper to make four boxes on each side. This will be your worksheet to turn in for a progress grade. O Complete problems in Holt math book on page rd and 6 th period: complete problems 33–40 4 th and 5 th period: complete problems 29–36 O First, copy the original problem on your paper, then solve. Please circle your answers. O 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).