Working with Fractions, Decimals and Percentages

Percentage to decimal

• A percentage counts hundredths, so dividing by 100 recovers the decimal
• Dividing by 100 shifts every digit two columns to the right
  • 8% becomes 0.08
  • 65% becomes 0.65
  • 240% becomes 2.4
  • 0.5% becomes 0.005
• A percentage above 100 always gives a decimal above 1

Decimal to percentage

• Multiplying by 100 reverses the process and shifts every digit two columns left
  • 0.47 becomes 47%
  • 2.06 becomes 206%
  • 0.009 becomes 0.9%
• The per cent sign must be written, since 47 and 47% are different quantities