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

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

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

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.

Example Decimal way Find 22% of 250.

Example Fraction Way Find 22% of 250.

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

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

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

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

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

Answers Find 42% of 70 = 29.4 Find 8% of 210= 16.8 Find 11% of 600= 66