Exercise 1 Page 378

Fractions, decimals, and percents are three ways to show parts of a whole. We want to write a decimal as a fraction and as a percent. Let's do these things one at a time.

Fraction

To write a decimal as a fraction, we start by writing the number as the numerator and

1

as the denominator.

0.16 = \frac{0 . 1 6}{1}

Then, we can find an equivalent fraction with a whole number numerator. It is usually easiest to multiply by a power of

10

and then simplify.

\frac{0 . 1 6}{1}

ExpandFrac

$\frac{a}{b} = \frac{a \cdot 1 0 0}{b \cdot 1 0 0}$

\frac{0 . 1 6 \times 1 0 0}{1 \times 1 0 0}

Multiply

\frac{1 6}{1 0 0}

ReduceFrac

$\frac{a}{b} = \frac{a / 4}{b / 4}$

\frac{1 6 \div 4}{1 0 0 \div 4}

CalcQuot

Calculate quotient

\frac{4}{2 5}

We found that

0.04

expressed as a fraction is

\frac{1 6}{1 0 0},

or

\frac{4}{2 5} .

Percent

To write a decimal as a percent, we multiply by

100

and add the percent symbol

% .

We found that

0.16

expressed as a percent is

16 % .