Reteaching 6-1. Find each unit rate.

Transcription

1 Reteaching -1 Ratios and Unit Rates One store has -packs of juice for $.90. Another store has -packs of the same size juice cartons for $1.12. Which is the better buy? Find the unit rates. price S $.90 number S -pack: $.1>carton price S -pack: $1.12 number S $.1>carton The -pack has the lowest unit price. -pack $.90 -pack $1.12 Find each unit rate. 1. $91 in 1 h mi in h 3. $13.1 for 12 gal. 0 gal in 0 min. for oz. 92 words in min. A 12 fl oz bottle of shampoo costs $1.0 at Discount Mart. A fl oz bottle of the same shampoo costs $2. at Super Store. Find each unit rate and determine which is the better buy. 12 fl oz bottle: fl oz bottle: Better buy:. A school bus travels 3.3 mi on. gal of gas on its way to a museum for a field trip. On the return trip it takes the freeway and travels 3.2 mi on. gal of gas. Find the gas mileages of each trip and determine which is greater. To the museum: Returning from the museum: Better mileage: Pre-Algebra Chapter Lesson -1 Reteaching 11

2 Reteaching -2 Proportions Solve Method 1: Multiplication Property of Equality ? 10? Method 2: cross products Multiply each 0 Find the cross products. side by. Simplify. 0 1 Divide each side by. Simplify. Solve each proportion. When necessary, round to the nearest hundredth. p y t e.. m z r c y k w 2 a 0 2 t 10 e Lesson -2 Reteaching Pre-Algebra Chapter

3 Reteaching -3 Similar Figures and Scale Drawings Similar triangles have the same shape but not necessarily the same size. In the figures, nabc is similar to ndef. The symbol, means is similar to. nabc, ndef. The lengths of the sides of similar triangles are always proportional to each other. Find EF. AC Substitute into Write a proportion. Find the cross products. Divide each side by. Simplify. Use the properties of similar triangles to calculate the side lengths in each problem. 1. nmnp, nstw. a. Complete: ; b. Substitute the correct lengths in the above proportions and solve. 1 SW 3 2. ndkl, nrev. DK RV 3. nanf, nkgs. AN GS SW DF EF BC ; MN ST MP MN ST TW NP D A N K B A M 10 N 3 L R F C E 1 G K E S P 3 1 D 0 T F 2 V S W Pre-Algebra Chapter Lesson -3 Reteaching 13

4 Reteaching - Probability Suppose you select a letter at random from the words MIDDLE SCHOOL. Find P(L) and P(not L). First determine the number of possible outcomes. There are 12 letters in the two words, so there are 12 possible outcomes when you select a letter at random. Net determine the number of favorable outcomes for P(L). There are two L s. number of favorable outcomes Thus, P(L) number of possible outcomes You can find P(not L) several ways. Since there are 12 possible outcomes and 2 are L, are not L. number of favorable outcomes Thus, P(not L) number of possible outcomes Also P(not L) 1 2 P(L) A drawer contains red socks, blue socks, and 1 white socks. A sock is pulled from the drawer at random. Find the probability for each case. 1. P(red) 2. P(blue) 3. P(red or white). P(red, white, or blue). P(not red). P(green) Suppose you spin a spinner that is equally likely to land on any one of the numbers from 1 to. Find the probability for each event.. P(1). P(an odd number) 9. P(a number divisible by ) 10. P(2) 11. P(a number with a 1 in it) 12. P(a prime number) 13. P(a number less than ) 1. P(a number) 1. P(a number that is not less than 1) 1. P(a number divisible by 3 or ) 1 Lesson - Reteaching Pre-Algebra Chapter

5 Reteaching - Fractions, Decimals, and Percents Write as a percent and % as a fraction in lowest terms. Divide =.% Thus.%. Write each fraction as a percent Write each percent as a fraction in simplest terms. % means parts per 100. % ? Thus % % % 13. % 1. 1% 1. 0% 1. 9% % 1. 30% 19. 2%..% Pre-Algebra Chapter Lesson - Reteaching 1

6 Reteaching - Proportions and Percents What percent of 9 is 2.? You can solve percent problems by writing and solving a proportion. Any percent problem of the form % of a is b can be written as: 100 b a so , , is 2% of 9. Write a proportion. Write cross products. Divide each side by 9. Simplify. Write a proportion. Then solve. Where necessary, round to the nearest tenth or tenth of a percent. 1. What percent of is 0? 2. What percent of is 1? 3. What percent is 1 of 2?. What percent of 1 is?. What percent of 1 is 12?. What percent of 9 is 2?. Find 2% of 1.. Find % of. 9. Find % of Find % of Find 3% of Find 1% of % of is 2. What is? 1. 9% of k is 2. What is k? 1. % of p is 12. What is p? % of h is 2. What is h? 1. 13% of r is 9. What is r? 1. % of j is. What is j? 1 Lesson - Reteaching Pre-Algebra Chapter

7 Reteaching - Percent of Change Find the percent of decrease from to 0. Find the amount of decrease percent of decrease 2 amount of decrease original amount < % The percent of decrease is about 29.% Find each percent of increase. Where necessary, round to the nearest tenth of a percent is increased to is increased to is increased to is increased to.. 2 is increased to is increased to is increased to 9.. is increased to 132. Find each percent of decrease. Where necessary, round to the nearest tenth of a percent is decreased to is decreased to is decreased to is decreased to is decreased to is decreased to is decreased to is decreased to Lesson - Reteaching Pre-Algebra Chapter

8 Reteaching -9 Markup and Discount A store pays $ for a basketball. The markup is 0%. Later, they discount the basketball 2%. Find the original selling price and the sale price of the basketball. Method 1 Method 2 The markup is 0% of the cost. The selling price equals 100% of the cost plus Find 0% of $. 0.() $.0 0% (the markup) of the cost, or 10%. Find 10% of $. Store s cost 1 markup selling price 1.0() $ $12.0 The original selling price is $12.0. The original selling price is $12.0. The discount is 2% of the original The sale price is 100% of the original price minus selling price. 2% of the original price, or %. Find 2% of $12.0 Find % of $ (12.0) 3. 0.(12.0) $9.0 original price 2 discount sale price The sale price is $ The sale price is $9.0 Complete each table. Where necessary, round to the nearest cent Cost Markup Selling Price $1 0% $ 0% $110 % $ % $33 3% Original Discount Selling Price $19 2% $13 1% $9 30% $ % $2.9 3% Sale Price Pre-Algebra Chapter Lesson -9 Reteaching 19

9 Reteaching -10 Make a Table A saving account pays % interest per year. You deposit $1,000 and then do not deposit or withdraw any money. How much will be in the account at the end of years? A table can help you solve the problem. The first year, your interest is % of $1,000 or $0. At the end of the first year and the beginning of the second year, you have $1,00. The second year, your interest is % of $1,00 or $1.0. If you finish the table, you find you have $1,21. at the end of years. A savings account pays % interest per year. You deposit $1,00 and then do not deposit or withdraw any money. Complete the table to find out how much will be in the account at the end of 10 years Year Beginning Balance Interest Ending Balance 1 $1,000 $0 $1,00 2 $1,00 $1.0 $1, $1,01.0 $3.2 $1,12. $1,12. $.99 $1,19. $1,19. $.9 $1,21. Year Beginning Balance Interest Ending Balance 1 $1, Amount: Lesson -10 Reteaching Pre-Algebra Chapter