New
New
Lesson 4 of 11
New
New
- Year 10
Percentage profit and loss
I can calculate percentage profit and percentage loss.
Lesson details
Key learning points
- When calculating percentage profit or loss, you are interested in the change.
- If the final amount is more than the original, there is profit.
- If the final amount is less than the original, there is loss.
- This change can be described as a percentage of the original amount.
- A negative percentage is interpreted as a loss.
Keywords
Percentage profit - is the increase when referencing something that is sold for more than the cost price given as a percentage of the original amount
Percentage loss - is the decrease when referencing something that is sold for less than the cost price given as a percentage of the original amount
Common misconception
When using multipliers, pupils can mistake a decimal for the percentage decrease. e.g. 0.52 is a 52% decrease, rather than recognising a 48% decrease
Reminding students that a decimal multiplier greater than 1 means an increase, and a decimal multiplier less than 1 means a decrease. The latter requires a subtraction from 1 or 100%
Have a conversation about progress and how progress is relative. The concept of relative progress is difficult for students to have. How can a child have an IQ of 100 and a adult have an IQ of 100? IQ is relative to age. Percentage profit or loss is relative to the original amount.
Teacher tip
Licence
This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Increase 65 by 5%
Increase 65 by 5%
Q2.Decrease 60 by 5%
Decrease 60 by 5%
Q3.If a number increases by 70% and is now 85, what was it originally?
If a number increases by 70% and is now 85, what was it originally?
Q4.Decrease 250 by 15%
Decrease 250 by 15%
Q5.A mathematician celebrates their shares increasing by 12% which are now worth £100.80. How much did they originally invest?
A mathematician celebrates their shares increasing by 12% which are now worth £100.80. How much did they originally invest?
Q6.If a number increases by 82% and is now 163.8, what was it originally?
If a number increases by 82% and is now 163.8, what was it originally?
Assessment exit quiz
6 Questions
Q1.If I increase £45 to £54, what is the percentage gain?
If I increase £45 to £54, what is the percentage gain?
Q2.If I increase £45 to £99, what is the percentage gain?
If I increase £45 to £99, what is the percentage gain?
Q3.If I increase £14 to £56, what is the percentage gain?
If I increase £14 to £56, what is the percentage gain?
Q4.If I decrease £90 to £18, what is the percentage loss?
If I decrease £90 to £18, what is the percentage loss?
Q5.If I decrease £88 to £66, what is the percentage loss?
If I decrease £88 to £66, what is the percentage loss?
Q6.Match the following so that the number on the right reflects a 20% percentage loss on the number on the left.
Match the following so that the number on the right reflects a 20% percentage loss on the number on the left.
