1. DO NOW

2. OBJECTIVE : SWBAT Solve problems involving proportional relationships Convert between measurement systems using unit rates and using proportions

3. Answers Questions on Page 87

4. Vocabulary Review A ratio is a comparison of two quantities by division. ̶17 out of 20 students, or A rate is a special type of ratio comparing two quantities with different units. – Driving 120 miles in 2 hours, or A unit rate is a rate that is simplified so that it has a denominator of 1 unit. – Driving 120 miles in 2 hours, or

5. Example : The price of three different bags of cat food are shown in the table to the right. Which bag has the lowest price per pound? Write a verbal model of what you are comparing. For the 3.5 lb bag, The 7 pound bag is the least expensive at $1.35 per pound Cat Food Prices Size of bag (lbs) Price ($) 3.54.83 79.45 2027.20 For the 7 lb bag, For the 20 lb bag,

6. NOW Try page 88 #25 to 31 Think Pair Share-shoulder partners

7. Properties of a proportion? 2x6=12 3x4 = 12 3x4 = 2x6 Cross Product Property

8. Review: How to Solve the Proportion k 17 = 20 68 Start with the variable. = 68k17(20) Simplify. 68k=340 Now we have an equation. To get the k by itself, divide both sides by 68. 68 k = 5

9. Ex: Solve the proportion If the proportion is to be true, the cross products must be equal  find the cross product equation:  24 = 3n – 6  24 = 3(n – 2)  30 = 3n  10 = n Check: x 2

11. NOW Try page 88 #32 to 45 Think Pair Share-shoulder partners

14. Summary How do we use proportions to solve problems?

15. Homework Page 84 # 6 to 8 and Page 86 #4 and 5