WARM UP TODAYS LESSON SOLVING PROPORTIONS March 7

WARM UP

“ TODAY’S LESSON: SOLVING PROPORTIONS March 7, 2014 ”

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)

BRAINSTORM… • What do you remember about proportions?

WHAT ARE PROPORTIONS? • A Proportion is an equation that states that two ratios are equal.

HOW CAN YOU FIND TWO RATIOS THAT ARE EQUAL? • For example find two ratios that are equivalent to: Multiply by a factor Divide by a common factor

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

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

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 12 = 12 2 x 4=8 9 x 1=9 9≠ 8

YOU TRY SOME EXAMPLES!!!!!

LET’S TAKE IT UP A NOTCH!!! • Cross multiply! • Example:

YOU GOT IT HOW ABOUT YOU TRY SOME ON YOUR OWN!!!!!

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?

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?

PROPORTION ACTIVITY Speed Dating ( Proportion Style)!!!!