01Why this matters
Knowing the final price helps you compare offers without being distracted by the size of the advertised percentage.
02See it
03Understand it
A discount reduces a price by a specified amount or a percentage of the original price.
First find the saving, then subtract it from the original price. Alternatively, multiply the original price by the fraction remaining. A 20% discount leaves 80% of the price. Consecutive discounts act on different starting amounts and cannot usually be added.
04Guided example
A $120 jacket is discounted by 25%. What do you pay?
- Find the saving: 120 × 25/100 = $30.
- Subtract the saving from the original: 120 − 30 = $90.
- Check another way: 75% remains, and 120 × 0.75 = $90.
05Try it
06Practise it
07Use it in the real world
A $40 product with 15% off costs $34. Comparing that final price with a $33 competing product is more useful than comparing sale labels.
Go a little deeper
To reverse a discount, divide by the remaining fraction. A $90 price after 25% off came from 90 ÷ 0.75 = $120. This does not work for a 100% discount because the remaining fraction is zero.
08Quick check
09Summary
A discount reduces a price by a specified amount or a percentage of the original price. Check another way: 75% remains, and 120 × 0.75 = $90.
Before moving on, explain the worked example in your own words. Use the hint on any question you want to revisit.
10Key idea
final price = original × (1 − discount/100)
Prices use the same currency; discount is a percentage from 0 to 100.
original = final price / (1 − discount/100), for discount < 100
Find this in the formula library →