Decimals, Fractions, and Percents

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 1.Divide the numerator by the denominator. 2.Do this until you get a decimal that terminates or repeats. 3.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 (terminating decimal) Example 2: Convert 2/3 to a decimal 2/3= 2 ÷ 3= 0.66 (repeating decimal)

Converting Fractions to Percent 1.Change the fraction to a decimal 2.Multiply the decimal by 100 (move two places to the right) 3.Put a percent sign (%). Example 1: Convert 1/2 to a percent 1/2= 1÷ 2 = 0.50 (terminated) 0.50*100= 50 =50% Example 2: Convert 1/3 to a percent 1/3= 1÷3= 0.33 (repeating) 0.33*100= 33 =33%

Converting Decimals to Fractions 1.Place the number that follows the decimal point over the place that it is in ( tenths, hundredths, thousandths, etc.). 2.Simplify as necessary. Example 1: Convert 0.7 to a fraction 0.7 = 7/10 ( 7 is in the tenths place ) Example 2: Convert 0.25 to a fraction 0.25= 25/100= 1/4 (25 is in the hundredths place. the GCF of 25 and 100 is 4 therefore 1/4 is the simplest form of 25/100) Example 3: Convert to a fraction 1.625= 1 625/1000= 1 5/8 ( 625 is in the thousandths place. 5/8 is the simplified form of 625/1000)

Converting Decimals to Percent 1. 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 0.20*100= 20 = 20% Example 2: Convert 4 to a percent 4*100= 400 = 400%

Converting Percent to Fractions 1.Change the percent to a decimal (÷ the % by 100 or move the decimal point 2 places to the left) 2.Put the numbers behind the decimal point over the place that it is in ( tenths, hundredths, thousandths, etc.). 3.Simplify as necessary Example 1: Convert 85% to a fraction 85% = 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 fraction 12.5%= 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 Percent to Decimals 1.Divide the percent by 100 or move the decimal point 2 places to the left Example 1: Convert 72% to a decimal 72%= 72÷ 100= 0.72 Example 2: Convert 62.5% to a decimal 62.5%= 62.5÷ 100= 0.625