Percentages
Maths: Edexcel IGCSE Higher, topic 1.6.1
Percentages
A percentage is ‘parts per hundred’ and is written with a % sign which is called ‘percent’.
More than 100%
- A percentage of more than 100% will be bigger than the original number.
- A percentage of 350% is 3.5 times bigger than the original number.
- It represents a percentage increase of 350% - 100% = 250%.
Less than 100%
- A percentage of less than 100% will be smaller than the original number.
- 65% represents a percentage decrease of 100% - 65% = 35%.
Percentages
A percentage is ‘parts per hundred’ and is written with a % sign which is called ‘percent’.
Finding a percentage
- To find a certain % of a number, convert the percentage to a decimal then multiply by the original.
Converting Percentages
A percentage is ‘parts per hundred’ and is written with a % sign which is called ‘percent’.
Percent to fraction
- To convert between a percentage and a fraction write the number before the percent sign on the top and 100 on the bottom.
- 45% is 45 parts per 100 so is equivalent to the fraction 45⁄100 = 9⁄20.
Percent to decimal
- To convert from a percentage to a decimal simply divide by 100 and remove the percent sign.
- 45% is equivalent to the decimal 0.45.
Test yourself on Percentages
Which of the following defines percentage?
What is 150% of 150?
What is 200% of 15?
What is 60% of 120?
What percentage decrease is represented by 45% of a number?