1. Learning Target:Students will learn how to calculate decimal numbers and whole numbers by multiplying. Students will learn the communicative and associative properties of multiplication.
2. Rule:Multiply like normal. Then count the number of place values behind (to the right) the decimal point in the problem.Start at the right of the product and move the decimal the number of placed to the left that you counted from in the step above.
7. Properties of Multiplication:Commutative Property – You can multiply numbers in any order2 6.5 = 6.5 2a b = b aAssociative Property – Changing the grouping of factors will not change the product.(2 6.5) 4 = 2 (6.5 4)(a b) c = a (b c)
8. Tell which property of multiplication is shown. Explain your choice. (3.25 5) 2 = 3.25 (5 2)0.4 32 5 = 32 0.4 5
9. (3.25 5) 2 = 3.25 (5 2)Associative property of multiplication(changing the grouping) 0.4 32 5 = 32 0.4 5Commutative property of multiplication(changing the order)
10. You complete the first leg of a bike race in about 12 hours over two days. Your cyclometer shows that your average speed for this leg was 15.95 miles per hour. About how long was this leg of the race?