1. Warm Up

2. Today’s Lesson: Solving Proportions
March 7, 2014

3. Before we begin……….
This is a rare occasion in my class guess what…………………………?
You can use your cell phones on an activity today(Just for the activity I will still take phones if they are not used appropriately)
What I need you to do is if you have a smart phone download the QR code reader if you do not have it already(QR Droid)

4. Brainstorm…
What do you remember about proportions?

5. Can be written using a fraction or using a “:”
What are Proportions?
A Proportion is an equation that states that two ratios are equal.
Ratio:A comparison of two quantities by division.
Can be written using a fraction or using a “:”
Ex. a 7:5 ratio can be stated as “seven to five ratio”, it could also be written as a fraction: 7 5

6. How can you find two ratios that are equal?
Divide by a common factor
For example find two ratios that are equivalent to:
Multiply by a factor

7. Finding if ratios are equivalent
Method 1: Simplify both fractions and they should be the same
Method 2: Cross multiply and the numbers should be the same

8. How else do I know if ratios are proportional (equivalent)? Method 1
The fractions are the same when they are simplified!
Ex. Simplify these two fraction and tell if they are proportional:
So they ARE proportional

9. How can you tell if ratios are proportional (equivalent)? Method 2
Cross multiply (also called cross products) and you should get the same number for each.
Examples:
3 x 4 = 12
12 x 1 = 12
2 x 4 = 8
9 x 1 = 9
12 = 12
9 ≠ 8
Proportional
NOT Proportional

10. You try some examples!!!!!

11. Let’s take it up a notch!!!
Cross multiply!
Example:

12. You got it how about you try some on your own!!!!!!!!!!

13. Time for a Word problem
Jen is making oatmeal chocolate chip cookies. The recipe will make 4 dozen cookies and calls for 3 cups of oatmeal. How many cups of oatmeal would Jen need to use in the recipe if she wants to make 6 dozen cookies?

14. You Try!!! Set up the proportion and solve.
A nut mixture uses 2 cups of almonds to 3 cups of cashews. If you have 7 cups of cashews to use, how many cups of almonds would you need to make the nut mixture?

15. Speed Dating ( Proportion Style)!!!!
Proportion Activity
Speed Dating
( Proportion Style)!!!!