Percentage Basics & Introduction- By Kari Knisely

What you will learn…

Where percents come from

What percents are

What percents look like

Common percentages used in everyday life

Why we use percents

Where Percents Come From

Italian roots most commonly assumed

Where did percents come from?

Encyclopedia/Merriam-Webster – click here for more information

Merriam-Webster – click here for more information

Merriam-Webster Dictionary. Retrieved on March, 24 2012 from http://www.merriam-webster.com/dictionary/percent

What Percents are & Basic Info

Converts any quantity into a part of 100 to easily compare

What is a Percent?

cent Per

Per 100100

÷

%= parts per 100

Percents as Fractions

Steps1.Percentage number becomes numerator2.Denominator becomes 1003.Remove the percent sign4.Simplify

75 %

75100

75100

2525

34

75 %

34

Percents as Decimals

Steps1.Move decimal 2 places left2.Remove the percent sign3.Re-write decimal

75 %

75.0 %

75.0 %

0.75

Is more than 100% possible?

200%

Is more than 100% possible?

175%

75%

What does a percent look like?

%

What does a percent look like?

What does a percent look like?

40 Test Questions = 100% = 1.0

What does a percent look like?

40 Test Questions = 100% = 1.0

50%20 ?s0.50

50%20 ?s0.50

What does a percent look like?

40 Test Questions = 100% = 1.0

25%10 ?s0.25

25%10 ?s0.25

25%10 ?s0.25

25%10 ?s0.25

What does a percent look like?

40 Test Questions = 100% = 1.0

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

12.5%5 ?s0.125

Common Percentage Types

Discounts & Sales

Tips

Taxes

Common Percentage Types

Common Percentage Types

Calculate

Common Percentage Types

Calculate

Common Percentage Types

Common Percentage Types

Calculate

Common Percentage Types

Calculate

Common Percentage Types

Common Percentage Types

Calculate

Original $24.99 Discount - 7.50

Sale Price $17.49

FL Tax Rate 6% = ?

Common Percentage Types

Calculate

Original $24.99 Discount - 7.50

Sale Price $17.49

FL Tax Rate 6% = ?

Why do we use percents?

Compare different quantities

Why do we use percents?

Brad’s Math Test45 questions correct

Kim’s Science Test 52 questions correct

IF 50 questions total

IF 60 questions total

Why do we use percents?

0 % 25% 50% 75%

100%

If 50 total ?s

25 ?s 37.5 ?s 50 ?s12.5 ?s0 ?s

45 ?s

≈ 90%

Brad’s Math Test45 questions correct

IF 50 questions total

Why do we use percents?

0 % 25% 50% 75%

100%

If 60 total ?s 30 ?s 60 ?s45 ?s15 ?so ?s

52 ?s

≈ 87%

Kim’s Science Test 52 questions correct

IF 60 questions total

Why do we use percents?

0 %

0 %

25%

25%

50%

50%

75%

75%

100%

100%

If 50 total ?s

If 60 total ?s

25 ?s

30 ?s 60 ?s45 ?s15 ?so ?s

37.5 ?s 50 ?s12.5 ?s0 ?s

45 ?s

52 ?s

≈ 90%

≈ 87%

Why do we use percents?

Brad’s Math Test45 questions correct

Kim’s Science Test 52 questions correct

IF 50 questions total

IF 60 questions total

= 90%

= 87%

Why do we use percents?

Brad’s Math Test16 questions correct

Kim’s Science Test 16 questions correct

IF 20 questions total

IF 24 questions total

Why do we use percents?

0 % 25% 50% 75%

100%

If 20 total ?s

10 ?s 15 ?s 20 ?s5 ?s0 ?s

16 ?s

≈ 80%

Brad’s Math Test16 questions correct

IF 20 questions total

Why do we use percents?

0 % 25% 50% 75%

100%

If 24 total ?s 12 ?s 24 ?s18 ?s6 ?so ?s

16 ?s

≈ 65%

Kim’s Science Test 16 questions correct

IF 24 questions total

Why do we use percents?

0 %

0 %

25%

25%

50%

50%

75%

75%

100%

100%

If 20 total ?s

If 24 total ?s

10 ?s

12 ?s 24 ?s18 ?s6 ?so ?s

15 ?s 20 ?s5 ?s0 ?s

16 ?s

16 ?s

≈ 80%

≈ 65%

Why do we use percents?

Brad’s Math Test16 questions correct

Kim’s Science Test 16 questions correct

IF 20 questions total

IF 24 questions total

≈ 80% ≈ 65%

What you have learned…

Where percents come from

What percents are

What percents look like

Common percentages used in everyday life

Why we use percents

Works Cited

All images retrieved from Google images

Why do we use percents?

0 %

0 %

25%

25%

50%

50%

75%

75%

100%

100%

If 20 total ?s

If 24 total ?s

10 ?s

12 ?s 24 ?s18 ?s6 ?so ?s

15 ?s 20 ?s5 ?s0 ?s

16 ?s

16 ?s

≈ 80%

≈ 65%

Why do we use percents?

0 %

0 %

25%

25%

50%

50%

75%

75%

100%

100%

If 50 total ?s

If 60 total ?s

25 ?s

30 ?s 60 ?s45 ?s15 ?so ?s

37.5 ?s 50 ?s12.5 ?s0 ?s

45 ?s

52 ?s

≈ 90%

≈ 87%