Proportions and Fractions

Math Workshop 3rd Period

Monday, December 6, 2010

Agenda

Bell Ringer Mixed Numbers on the PowerPoint Gallery Walk on Mixed Numbers Proportions on the PowerPoint Independent Work on Proportions Start Homework (due on Wednesday)

Objective

By the end of the unit, students will be able to add, subtract, multiply, and divide

fractions, find squares and square roots, solve proportions and use scientific

notation.

Mixed Numbers

What is 2 3/4 + 2 ½ ?

In your calculator:(2 + ¾) + (2 + ½) = 5.255.25 – 5 (subtract the whole number) .25MATH ENTER ENTER¼ 5 ¼

What is 8 1/7 / 2 1/5 ? In your calculator:

(8 + 1/7) / (2 + 1/5) = 3.7012987013.701298701 – 3 (subtract the whole

number).701298701MATH ENTER ENTER54/77 3 54/77

What is 4 2/6 – 2 1/3 ?

In your calculator:(4 + 2/6) - (2 + 1/3) = 2

What is 3 1/9 x 5 4/6 ?

In your calculator:(3 + 1/9) x (5 + 4/6) = 17.6296296317.62962963 - 17(subtract the whole number) .62962963MATH ENTER ENTER17/27 17 17/27

Gallery Walk

Students will walk around the room and answer the math questions and turn in their worksheet once they are finished.

This is an assessment and students should be quiet when walking. If you have

a question, please ask Ms. Kmiecik.

Proportions

A proportion is an equation of the form

a = c

b d

• The two ratios have to be equivalent. a/b = c/d.

• If they are not equal, it is not a proportion.

4 = 83 6

Are the ratios above a proportion? Cross Multiply 4 and 6 = 24 Cross Multiply 3 and 8 = 24 Are the numbers even? Yes! It is a proportion!

Solve the Proportion 12 = x 2 4

Cross Multiply 12 and 4 12 x 4 = 48 Cross Multiply 2 and X 2 x X = 2x Divide by number in front of the variable (x) 48 = 2x

2 2 24 = X

Solve the Proportion 15 = x 3 4

Cross Multiply 15 and 4 15 x 4 = 60 Cross Multiply 3 and X 3 x X = 3x Divide by number in front of the variable (x) 60 = 3x

3 3 20 = X

If Ms. Kmiecik can make 30 Christmas cookies with 4 cups of sugar, how many cups of sugar will

she need for 90 Christmas cookies?

Set up the proportion 30 (Christmas cookies) = 90 (Christmas cookies) 4 (cups of sugar) x (cups of sugar) Cross Multiply 30 and x 30 x X = 30x Cross Multiply 90 and 4 90 x 4 = 360 Divide by the number in front of the variable (x) 360 = 30 x 30 30 12 = X 12 cups of sugar are needed to make 90 Christmas cookies

Proportions

Students will now complete 15 proportion problems and turn in before class finishes.

Homework

Students will be given the rest of class to work on their homework. Please ask Ms.

Kmiecik if you have any questions.