Fractions, Decimals, and PercentagesREVIEW CONCEPTS

Mathematical Relationship

Fractions, decimals and percentages are different ways to describe a part of a whole.

Look at the ruler below:

We can say that the area shaded green is 50% of an inch, or ½ an inch, or 0.5 of an inch. These are all the same quantity.

You can convert any one form to the other.

Fractions

PercentagesDecimals

Convert a Fraction to a Decimal

Divide the numerator by the denominator.

Examples:

5 25 75

NOTE: The line above the three indicates that digit repeats

infinitely.

Convert a Decimal to a Fraction

Place the number over the place value of the last digit. Drop the decimal and reduce the fraction to lowest terms.

Example:

0.625 The last digit is in the thousandths place. Put it over 1000.

Drop the decimal in the numerator.

Reduce the fraction to lowest terms. In this case, we can reduce by 125.

Convert Decimal to a Percentage

Simply multiply the decimal by 100.

Examples:

NOTE: Decimals greater than one will be greater than 100%.

(1=100%)

Convert Percentages to a Decimal

Simply divide the decimal by 100.

Examples:

Convert Fractions to a Percent

Find an equivalent fraction with the denominator of 100.

NOTE: You may find it easier to convert the Fraction to a Decimal

and then to a Percentage.

Convert Percentages to Fractions

Drop the percentage symbol and place the digits over 100. Reduce.

NOTE: Percentages over 100% will result in a mixed fraction

Putting it All Together

Fraction Decimal Percent

Take these common measurements and convert them as required to fill the table.

Putting it All Together

Fraction Decimal Percent

Take these common measurements and convert them as required to fill the table.

Putting it All Together 8 out of 50 employees called in sick. What percent of employees called in sick?

16% of employees called in sick.

Putting it All Together In a sample of alloy, 5% is nickel. Represent this as a fraction.

of the alloy is nickel.

Your turn!!!