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Proportions and Fractions. Math Workshop 3 rd 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.
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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.
What is 2 3/4 + 2 ½ ? • In your calculator: • (2 + ¾) + (2 + ½) = • 5.25 • 5.25 – 5 (subtract the whole number) • .25 • MATH ENTER ENTER • ¼ • 5 ¼
What is 8 1/7 / 2 1/5 ? • In your calculator: • (8 + 1/7) / (2 + 1/5) = • 3.701298701 • 3.701298701 – 3 (subtract the whole number) • .701298701 • MATH ENTER ENTER • 54/77 • 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) = • 17.62962963 • 17.62962963 - 17(subtract the whole number) • .62962963 • MATH ENTER ENTER • 17/27 • 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.