Lesson 3.1.2 – Teacher Notes Standard: 6.RP.3c Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent. Chapter 9 – Heavy focus on percentages Lesson Focus: You are defining a percent and introducing the percent ruler as a strategy to represent equivalent portions in different forms. (Maybe use 3-29 as an exit ticket or closure.) (3-27 and 3-28) I can convert among fractions, decimals, and percents. Calculator: Yes Literacy/Teaching Strategy: Turn and Talk

BELLWORK

p. 106 3-22 to 3-29

3-26 (cont.) In your sample there are 22 raisins and 18 peanuts Represent the portion of raisins in the whole sample as a fraction. How could someone tell the size of the whole sample by looking at your fraction? Explain. Recall that the definition of “percent” means “out of 100.” Use a Giant One to change your fraction from part (a) to a percent.

FOCUS QUESTION 3-27. USING A PERCENT RULER With your team, you will use the percent ruler shown above to examine a sample of 40 raisins and peanuts. Copy the percent ruler onto your paper. Then use it to determine how many raisins would make 50% of the sample. How many raisins are in 10% of the sample? Use your percent ruler to calculate the percent of raisins in the sample you were given in problem 3-26. Which method do you prefer, using a Giant One or a percent ruler? Why?

FOCUS QUESTION 3-28. How can the percent you found in problem 3-27 help you predict how many total raisins that might be in different amounts of mix?  Work with your team to draw a diagram to help you make sense of each of the following questions.  Be prepared to explain your thinking to the class. What if your sample had contained a total of 100 peanuts and raisins?  How many raisins would you predict would have been in that sample?  What if your sample had contained a total of 150 peanuts and raisins?  How many raisins would you predict would have been in that sample?  What if your sample had contained a total of 82 peanuts and raisins?  How many raisins would you predict would have been in that sample? 

3-30. LEARNING LOG Write your own definition of the word “percent.” Then describe at least one method to find a percent from a sample.

PRACTICE Lucy is taking advantage of the sale at Hollister. She wants to figure out how much she will save on a purchase of $40. Lucy’s percent ruler is shown below. Help her figure out 30% of $40. $40

PRACTICE (cont.) Mario really needs new shoes for school. He sees that Foot Locker has a sale for 40% off Nike shoes. Mario likes a pair that cost $90. Use the percent ruler below to determine how much Mario will save. $90

HOMEWORK