Finding a percent of a number

1. By, Mrs. Muller Finding a percent of a number

2. Key Vocabulary • Percent: a ratio that compares a number to 100.

3. Why Learn It? • To estimate the tip at a restaurant. • Find the Sales Tax • To find the sale price • To find out the test score on a test

4. The Procedure • For problems such as % of a number • First write the percent as a decimal. • Second Multiply the number and the decimal together. Another Way • First write the percent as a fraction in simplest form. • Divide the whole number and the denominator of the fraction by its GCD. • Third multiply the whole number to the fraction.

5. Example Decimal way • Find 22% of 250.

6. Example Fraction Way • Find 22% of 250.

7. Which way do you like best? • Do you prefer working with the decimal format or do you prefer working with the fractions? Why?

8. Helpful Table

9. Try on Your Own: Find the tip • For the following amounts give a 15% tip: • $9.85 • $52.00 • $30.00 • Now a 20% Tip • $9.85 • $52.00 • $30.00

10. Answers: • For the following amounts give a 15% tip: • $9.85= $1.4775; $1.48 • $52.00= $7.80 • $30.00= $4.50 • Now a 20% Tip • $9.85= $3.00 • $52.00= $10.40 • $30.00= $6.00

11. Try on your own: Examples • Find 42% of 70 • Find 8% of 210 • Find 11% of 600 • Find 65% of 240 • Find 70% of 185 • Find 15% of 90 • Find 7% of 50

12. Answers • Find 42% of 70 = 29.4 • Find 8% of 210= 16.8 • Find 11% of 600= 66 • Find 65% of 240= 156 • Find 70% of 185= 129.5 • Find 15% of 90= 13.5 • Find 7% of 50= 3.5