Pre-Algebra Demystified

Changing Fractions to Percents To change a fraction to a percent, change the fraction to a decimal (i.e., divide the numerator b ...

EXAMPLE Write 1^14 as a percent. SOLUTION 114 ¼^54 1 : 25 4 Þ 5 : 00 4 10 8 20 20 0 114 ¼ 125 % EXAMPLE Write^56 as a percent. S ...

4. 6^34 5. 5 12 ANSWERS 1. 50% 2. 87.5% 3. 18% 4. 675% 5. 41:6% Changing Percents to Fractions To change a percent to a fraction ...

EXAMPLE Write 175% as a fraction. SOLUTION 175 %¼ 175 100 ¼ 110075 ¼ (^134) PRACTICE Write each of the following percents as fra ...

Draw a circle and place a horizontal line through the center and a vertical line halfway down in the center also. In the top sec ...

In Type 1 problems, you are given the base and the rate and are asked to find the part. From the circle: P¼RB. Here, then, you ...

Math Note: Always change the percent to a decimal or fraction before multiplying or dividing. PRACTICE Find 50% of 90. Find 24% ...

EXAMPLE What percent of 5 is 2? SOLUTION Draw the circle and place 5 in the ‘‘of’’ section and 2 in the ‘‘is’’ section (see Fig. ...

PRACTICE What percent of 10 is 3? 15 is what percent of 120? 8 is what percent of 40? What percent of 80 is 32? What percent of ...

Change 42% to 0.42 and divide: 2940.42¼700. EXAMPLE 36 is 80% of what number? SOLUTION Draw the circle and place 36 in the ‘‘is ...

ANSWERS 1. 2300 2. 300 3. 70 4. 90 5. 750 Word Problems Percent word problems can be done using the circle. In the lower left se ...

Change 95% to 0.95 and multiply 0.95 40 ¼38. Hence, the student got 38 problems correct. EXAMPLE A football team won 9 of its 1 ...

Change the 6% to 0.06 and divide:$1,110 0 : 06 ¼$18,500. Hence, the price of the automobile was $18,500. Another type of percen ...

In an English Composition course which has 60 students, 15% of the students are mathematics majors. How many students are math ...

Write 54.8% as a decimal. (a) 0.548 (b) 5.48 (c) 0.0548 (d) 5480 Write 175% as a decimal. (a) 0.175 (b) 1.75 (c) 17.5 (d) 1750 ...

(a) 2.875% (b) 28.75% (c) 287.5% (d) 2875% Write 72% as a fraction. (a) 7 25 (b) 7 102 (c) 1 72 (d) 18 25 Write 5% as a fract ...

(b) 24% (c) 41.6% (d) 72% 3% of what number is 90? (a) 2.7 (b) 270 (c) 300 (d) 3000 72% of 360 is what number? (a) 25.920 (b) 5 ...

CHAPTER 7 Expression and Equations Basic Concepts In algebra, letters are used as variables. Avariablecan assume values of numbe ...

and the ‘‘x’’ is a variable. When no sign is written between a number and a variable or between two or more variables, it means ...

EXAMPLE Evaluate 5(xþ3y) when x¼
5 and y¼3. SOLUTION 5 ðxþ3yÞ¼ 5 ð
5 þ 3 ð 3 ÞÞ ¼ 5 ð
5 þ 9 Þ ¼ 5 ð 4 Þ ¼ 20 PRACTICE Evaluate ...