Decimals, Fractions,

andPercents

Definitions • Decimal - Any number shown with a decimal

point; a number based upon tenths or hundredths. ( 0.2, 0.375, 86.4 )

• Fraction - One or more of the equal parts of a whole; a number usually expressed in the form a/b. ( 1/3, 2 5/8, 7/4 )

• Percent- The word percent comes from Latin and means “ for each hundred” or “ per hundred.” ( 70%, 6.5%, 4.09% )

Converting Fractions to Decimals

To convert a fraction to a decimal, divide the numerator by the denominator. Do this until you get a decimal that terminates or repeats. If it repeats,

place a bar (--- ) over the first number that repeats.

Example 1: Convert 3/4 to a decimal

3/4 = 3÷4= 0.75

Example 2: Convert 2/3 to a decimal

2/3= 2÷3= 0.66 ( repeating decimal )

Converting Fractions to Percents

To convert a fraction to a percent, change the fraction to a decimal. Then multiply the decimal by 100 and put a percent sign (%).

Another way is to move the decimal point two places to the right and put a percent sign (%).

Example 1: Convert 1/2 to a percent

1/2= 0.50 0.50x 100= 50.00 Answer: 50%

Example 2: Convert 1/3 to a percent

1/3= 0.333 0.333x 100= 33.300 Answer: 33.3 %

Converting Decimals to Fractions

In order to convert a decimal to a fraction, place the number that follows the decimal point over the place that the decimal ends in.Then simplify as necessary.

Example 1: Convert 0.7 to a fraction0.7= 7/10 ( 7 is in the tenths place )

Example 2: Convert 0.25 to a fraction0.25= 25/100= 1/4 ( 25 is in the hundredths place.)

Example 3: Convert 1.625 to a fraction1.625= 1 and 625/1000 now reduce…. 1 and 5/8

Converting Decimals to Percents

• In order to convert a decimal to a percent, either multiply the decimal by 100 and write the percent sign (%), or move the decimal point two places to the right and write the percent sign (%).

Example 1: Convert 0.20 to a percent

0.20x 100= 20.00= 20% or 0.20= 0. 2 0= 20%

Example 2: Convert 4.00 to a percent

4.00= 4.00x 100= 400.00= 400% or 4.00= 4. 0 0=400%

Converting Percents to Fractions

• When converting percents to fractions, change the percent to a decimal ( divide the percent by 100 or move the decimal point two places to the left ). Then put the numbers behind the decimal point over the place that it is in ( tenths, hundredths, thousandths, etc.). Then simplify as necessary.

Example 1: Convert 85% to a fraction85% = 85÷ 100= 0.85= 85/100= 17/20 ( 85 is in the

hundredths place. 17/20 is the simplified form of 85/100 )

Example 2: Convert 12.5% to a fraction12.5%= 12.5÷ 100= 0.125= 125/1000=1/8 ( 125 is in the

thousandths place. 1/8 is the simplified form of 125/1000 )

Converting Percents to Decimals

When converting a percent to a decimal, divide the percent by 100 or move the decimal point two places to the left and put the decimal point.

Example 1: Convert 72% to a decimal

72% 72÷ 100= 0.72 or 7 2 . 0= 0.72

Example 2: Convert 62.5% to a decimal

62.5% 62.5÷ 100= 0.625 or 6 2 . 5= 0.625