Algebra Demystified 2nd Ed

224 algebra De mystif ieD

Percents

A percent is a decimal number in disguise. In fact, the word “percent” literally

means “per hundred.” Remember that “per” means to divide and “cent” means

hundred, so 16% means 16 ÷ 100 or 16/100 = 0.16 (notice that we move the

decimal point to the left 2 places). Because the word “of” means to multiply,

we see that the statement, “16% of 25” translates into (0.16)(25) = 4.

EXAMPLE

Convert the percent to a decimal number and compute.

82% of 44

Writing 82% as a decimal number, we have 82% = 0.82, so 82% of 44

becomes (0.82)(44) = 36.08

150% of 6 is (1.50)(6) = 9

834 % of 24 is (0.0875)(24) = 2.1

0.65% of 112 is (0.0065)(112) = 0.728

PRACTICE

Convert the percent to a decimal number and compute.

1. 64% of 50 is __.


2. 126% of 38 is __.


3. 0.42% of 16 is __.


4. 18.5% of 48 is __.


5. 213.6% of 90 is __.

✔SOLUTIONS

1. 64% of 50 is (0.64)(50) = 32


2. 126% of 38 is (1.26)(38) = 47.88


3. 0.42% of 16 is (0.0042)(16) = 0.0672


4. 18.5% of 48 is (0.185)(48) = 8.88


5. 213.6% of 90 is (2.136)(90) = 192.24

EXAMPLE

Convert the percent to a decimal number and compute.

PRACTICE

Convert the percent to a decimal number and compute.