Decimals, Fractions and Percentages

Decimals, Fractions and Percentages

Decimals, Fractions and Percentages are just different ways of showing the same value:

• A Quarter can be written...

• ... as a fraction:  $\frac{1}{4}$  

• ... as a decimal: 0.25

• ... as a percentage: 25%

From Percent to Decimal

• To convert from percent to decimal divide by 100 and remove the % sign.

• An easy way to divide by 100 is to move the decimal point 2 places to the left:

From Decimal to Percent

• To convert from decimal to percent multiply by 100%

• An easy way to multiply by 100 is to move the decimal point 2 places to the right:

From Fraction to Percentage

• To convert a fraction to a percentage divide the top number by the bottom number, then multiply the result by 100%

• Example: Convert  $\frac{3}{8}$   to a percentage

• First divide 3 by 8: 3 ÷ 8 = 0.375

• Then multiply by 100%: 0.375 × 100% = 37.5%

• Answer :  $\frac{3}{8}\ \equiv\ 37.5\%$  

From Percentage to Fraction

• To convert a percentage to a fraction, first convert to a decimal (divide by 100),

• Then multiply top and bottom by 10 for every number after the decimal point (10 for 1 number,100 for 2 numbers, etc)

Multiple Choice

Convert the decimal 0.875 to a percent

• 0.875%

• 8.75%

• 87.5%

• 875%

Multiple Choice

Convert the decimal 4.025 to a percent.

• 0.4025%

• 4.025%

• 40.25%

• 402.5%

Multiple Choice

Convert 18.75% to a decimal

• 0.001875

• 0.1875

• 0.01875

• 1.875

Multiple Choice

 $Express\ \frac{5}{8}\ as\ a\ percent$  

• 58%

• 625%

• 62.5%

• 60.25%

Multiple Choice

 $Express\ \frac{17}{25}\ as\ a\ percent$  

• 34%

• 68%

• 51%

• 85%

Multiple Choice

Express 5% as a fraction

• $\frac{1}{5}$

• $\frac{1}{20}$

• $\frac{2}{5}$

• $\frac{1}{2}$

Multiple Choice

Express 32% as a fraction

• $\frac{3}{10}$

• $\frac{17}{50}$

• $\frac{9}{25}$

• $\frac{8}{25}$

Multiple Choice

Convert 3.5% to a decimal

• 0.0035

• 0.035

• 0.35

• 3.5