Multiplying Decimals

1. After completing your mountain math, practice the two problems below. Find the product and quotient for the following: 0.8 x 0.4 0.403 x 5

2. Vocabulary Dividend: The number that is being divided Divisor: The number that the dividend is being divided by. Will be the second number in a division problem. Ex. 12 ÷ 4 12 is the Dividend 4 is the divisor Quotient: The solution to a division problem.

3. Multiplying Decimals Step 1) Count the number of decimal places in the problem. Step 2) After multiplying, the solution should have the same number of decimal places. (Total decimal places) Ex. 2 decimals 2 decimal places places total in the solution

4. Lets try some problems Sage n Scribe Part 1 A is the Sage first 1) 1.31 x 2.4 2) 524 x 0.5

5. Dividing Decimals Step 1) Move the decimal in the Divisor to the right to make a whole number Step 2) Move the decimal in the Dividend to the right the same number of times Step 3) Move the decimal up for the solution. Step 4) Divide Ex.

6. Sage n Scribe Part 2 A is the Sage first 1) 10.261 ÷ 3.1 2 ) 16.8 ÷ 2.4 3) 2.25 ÷ 0.5 4) 29.5 ÷ 0.4

7. Multiplying and Dividing by 10, 100, and 1000 Multiplying by 10, 100, or 1000 Move the Decimal place the to the right based on how many zeros there are. Ex. 2.6 x 10 = 26 Ex. 2.6 x 100 = 260 Ex. 2.6 x 1000 = 2600 Dividing by 10, 100, or 1000 Move the Decimal place to the left based on how many zeros there are. Ex. 2.6 ÷ 10 = .26 Ex. 2.6 ÷ 100 = .026 Ex. 2.6 ÷ 1000 = .0026

8. Homework WB p. 205 (1-15 odd) and p. 207 (13-21 odd)

9. After Completing Mountain Math, Think About the Below Question Brainstorm and write down an idea as to how you would solve the following: What is 60% of 120?

10. Homework Check p. 205 p. 207 1) 12.47 13) $.23 3) 16.1964 15) 9.1 kg 5) 61.42 17) 78 7) 4.359 19) 3.4 9) 69.446 21) 1.2 11) 4.8 13) 12 x $.59 = $7.08 $.09 x 24 = $2.16

11. Notes: How to Find the % of a Number using Decimals Step 1) Convert the % to a Decimal Step 2) What does “of” mean? Multiply! So Multiply the decimal with the number. Ex. 60% of 120 I convert 60% to 0.6 Then I solve .6 x 120 The answer is 72 So, 72 is 60% of 120

12. But what does that mean? What does it mean when I say 60% of 120? I want to know what PART of 120 is 60%.... So I know that 72/120 = .6 And I know that .6 = 60% So then 72/120 = 60% What property is that? Transitive Property of Equality (That’s a mouthful!)

13. Vocabulary Transitive Property of Equality If a = b, and b = c, then a = c.

14. White Boards 1) 40% of 75 2) 103% of 50 ( O hh ! Tricky!) 3) Of the 450 students at Miller Middle School, 38% ride the bus to school. How many students ride the bus to school? 4) 225% of 8

15. White Boards 5) 1% of 4 6) 5% of 12 7) In 2004, there were 19,000 bulldogs registered by the American Kennel Club. Approximately 86% of this number were registered in 2003. How many bulldogs were registered in 2003?

16. Homework Percent of a Number Worksheet