1. MULTIPLYING DECIMALS Sixth Grade Math August 20, 2013

2. How do I multiply decimals using the standard algorithm for the operation? Essential Question:

3. Step 1: Write the longer number on top when setting up the problem. Line up the last digits of both numbers. Step 2: Multiply the numbers ignoring the decimal point(s). Step 3: Count the total number of digits to the right of each decimal point. Step 4: Start at the end of the product and move the decimals point to the left as many places as you counted in step 3.

4. Example 1  Multiply 0.3 and 0.5  Set up the problem 0.3  x 0.5 Multiply 15Count 1 1 2 Put the decimal point into the product. 15

5. Let’s See It Another Way Notice:  3 tenths of the columns are shaded  5 tenths of the rows are shaded  The number of shaded squares that overlap are 15 out the 100 squares 50 squares 30 squares 15 squares

6. Example 2 30 squares 80 squares 24 squares overlapping 0.3 x 0.8 0.24

7. Example 3  Find the product of 9.683 and 6.1 9.683 x 6.1 9683 + 580980 590663 59.0663 There are 4 digits behind the decimal point in the product.