 # Unit 5 Review Flashcards Unit 5 Review Flashcards ALA: Pre-Algebra Unit 5 Percentages.

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Unit 5 Review Flashcards Unit 5 Review Flashcards ALA: Pre-Algebra Unit 5 Percentages

X + X 100% is the WHOLE THING: 100% of 80 is 80

X + X 200% is the twice the whole: 200% of 80 is 160

X + X 50% is half: 50% of 80 is 40

X + X 25% is one-fourth: 25% of 80 is 20

X + X 10% is one-tenth, so move the decimal one spot to the left: 10% of 80 is 8

X + X 20% is twice as much as 10%: 20% of 80 is 16

X + X 15% is halfway between 10% and 20%: 15% of 80 is 12

X + X The meal cost \$12.00 What is a 20% tip?

X + X The meal cost \$12.00 10% of \$12.00 is \$1.20. Double that to get 20%, so the tip would be \$2.40.

X + X The meal cost \$25.00 A coupon gives you 20% off. How much will you pay?

X + X 10% of 25 is \$2.50. So 20% of 25 is double that, or \$5. You’ll save \$5, so you’ll pay \$20.

10 is 50% of what number?

One way: 50% means half. 10 is half of 20. Another way: Set up a proportion 50 = 10 50x = 1000, so x = 20. 100 x Another way: set up an equation 10 = 50% of x 10 =.5x x = 10/.5 = 20

10 is what percent of 50?

X + X One way: set up a proportion x = 10 100 50 50x = 1000, so x = 20. 10 is 20% of 50. Another way: equation 10 = x  50 so x =.2, which is 20%

What is 40% of 150?

In your head: 10% of 150 is 15. 40% is 4 times that much, or 4 x 15 = 60. Another way: proportion 40 = x 100x = 6000 so x = 60. 100 150 Another way: equation 40% of 150 = x, so.4(150) = x, so x = 60.

X + X 1.3% of children are allergic to peanuts. In a pediatric hospital with 2000 patients a year, how many would you expect to have peanut allergies?

X + X You could set up a proportion: 1.3 = x 100 2000 100x = 2600, so x = 26 kids allergic to peanuts.

30% of Americans have hay fever. Of those, 75% find over-the-counter allergy medications helpful. How many people in a town of 1200 would have hay fever that was NOT helped by over-the-counter medication?

X + X 30% of 1200 is 360 people with hay fever. 75% of these 360, or ¾ of them, ARE helped by over-the-counter meds. That’s 270 who ARE helped by the medicine. That leaves 360 – 270, or 90 people, who are NOT helped.

Change the percent to a decimal and a fraction: 43%

Change the percent to a decimal and a fraction: 43% =.43 = 43 100

Change the percent to a decimal and a fraction: 135%

Change the percent to a decimal and a fraction: 135% = 1.35 = 135 = 27 100 20

Change the percent to a decimal and a fraction:.6%

Change the percent to a decimal and a fraction:.6% =.006 = 6 = 3 1000 500

Change the decimal to a fraction and a percent:.6

Change the decimal to a fraction and a percent:.6 = 6 = 3 = 60% 10 5

Change the decimal to a fraction and a percent:.07

Change the decimal to a fraction and a percent:.07 = 7 = 7% 100

Change the fraction to a decimal and a percent: 3 8

Change the fraction to a decimal and a percent: 3 =.375 = 37.5% 8

You are done with the ALA Unit 5 Review