2 Converting Fractions to Decimals To convert a fraction to a decimal, divide the numerator by the denominator. You will 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 decimal3/4 = 3÷4= 0.75( terminating decimal)Example 2: Convert 2/3 to a decimal2/3= 2÷3= ( repeating decimal )
3 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 percent0.20x 100= 20% or 0.20= = 20%Example 2: Convert 4.00 to a percent4x 100=400% or 4.00= =400%
4 Converting Percents to Decimals When converting a percent to a decimal, either divide the percent by 100 and put the decimal point, or move the decimal point two places to the left and put the decimal point.Example 1: Convert 72% to a decimal72%= 72÷ 100= 0.72 or = 0.72Example 2: Convert 62.5% to a decimal62.5%= 62.5÷ 100= or = 0.625
5 Copy and complete this chart PercentageDecimal%.2787%%.028%%.5542%%.054%%.1771%%.987%
6 Converting Fractions to Percents To convert a fraction to a percent, change the fraction to a decimal ( by dividing the numerator by the denominator ). 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 percent1/2= 1÷ 2 = 0.500.50x 100= 50.00=50% or 0.50= = 50%Example 2: Convert 1/3 to a percent1/3= 1÷3= 0.3330.333x 100= =33.3% or 0.333= =33.3%
7 Another way to Convert Fractions to Percents Make a proportion by putting a 100 under the percent. Then use cross products or mental math. Then add a percent sign.Example 1: Convert 1/5 to a percentMultiply the top and the bottom by 20 so x = 20%Example 2: Convert 3/25 to a percentMultiply the top and the bottom by 4 so x = 12%
8 Try these:Work out your percentage if you got 12 out of 25 Work out your percentage if you got 15 out of 25Work out your percentage if you got 17 out of 20A player scores 4 times out of 10 shots. What percentage did they make?5. Calculate the score percentage if out of 15 shots 12 are successful48%60%85%40%80%
10 A percent change is an increase or decrease given as a percent of the original amount. Percent increase describes an amount that has grown and percent decrease describes an amount that has be reduced.
11 Percent of IncreaseThe original cost of a CD was $10. The same CD now costs $15. It increased $5.From $10 to $155Change decimal to a percent=0.51050%increase
12 Percent of DecreaseThe original cost of a basketball was $12. The same basketball now costs $9. It decreased $3.From $12 to $93Change decimal to a %=0.251225%decrease
13 Finding Percent Increase and Decrease Find each percent change. Tell whether it is a percent increase or decrease.Movie tickets went from $8 to $10Simplify the numerator.Simplify the fraction.= 0.25= 25%Write the answer as a percent.$8 to $10 is an increase, so a change from 8 to 10 is a 25% increase.
14 Finding Percent Increase and Decrease Find the percent change. Tell whether it is a percent increase or decrease.Shoes went from $75 to $30Simplify the fraction.Simplify the numerator.= 0.6Write the answer as a percent.= 60%75 to 30 is a decrease, so a change from 75 to 30 is a 60% decrease.