1. Finding a percent of a number
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 Percent 10% 20% 25% 50% 75% 80% Fraction 1/10 1/5 ¼ ½ ¾
4/5
Decimal
0.1
0.2
0.25
0.5
0.75
0.8

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

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