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Percents and Proportional Reasoning Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7
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Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Jan 03, 2016

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Page 1: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Percents and Proportional Reasoning

Percents, Fractions, and DecimalsFinding a Percent of a Number

Lessons 6.6 & 6.7

Page 2: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Find a percent of a quantity as a rate per 100

(e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.

Use ratio and rate reasoning to solve real-world and mathematical problems

CCS: 6.RP.3.

Page 3: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Students will be able to:

Represent percents in different but related ways, such as a ratio, a fraction and a decimal

Use proportions to solve percentage problems

Use decimals to calculate daily transactions (finding sales tax or figuring tips on restaurant bills)

Objectives

Page 4: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

A percent is a ratio that

compares a number to 100. It means “per 100.”

49 out of 100 is 49%.

Vocabulary

Page 5: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Imagine a decimal point in the place of the

percent sign, and move the decimal two spaces to the left (the same as dividing by 100).

Writing Percents as Decimals

26% .26

40% .40 .47% .07

Page 6: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Place the percent in a fraction with a denominator of

100. Simplify the fraction.

Writing Percents as Fractions

26% 26100

1350

75%75

10034

Page 7: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Move the decimal point two spaces to the

right, and add a % symbol (this is the same as multiplying by 100).

Writing Decimals as Percents

.34 34%

.19 19%

.125 12.5%.6 60%

1 100%

Page 8: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Divide the numerator by the denominator to

get a decimal. Change the decimal to a percent by moving

the decimal point to the right (multiply by 100).

Writing Fractions as Percents

625 0.24 24%

Page 10: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Finding a Percent of a Number

Should we use decimals OR proportions (fractions) OR

both???

Page 11: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Using a Proportion

Set up a proportion that uses the percent over 100.

Cross multiply to write an equation. Solve the equation.

To set up your proportion, think, “IS over OF equals PERCENT over 100.”

Page 12: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Example – What is 20% of 30?

= 20100

part

whole30x

=100x 30(20)=100x 600

100 100=x 6

Page 13: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Using a Decimal

Change the percent to a decimal. Multiply that decimal by the number you are

finding the percent of.

Page 14: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Example – What is 18% of 70?

18% = 0.18

0.18 x 70 = 12.6

Page 16: Percents, Fractions, and Decimals Finding a Percent of a Number Lessons 6.6 & 6.7.

Homework Time!Reteaching 6.6 and 6.7 Handout

Classwork Time!

Math at the Mall -practice percentages and finding the best deal while shopping at a virtual mall