30% off £50 removes £15, leaving £35.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Work with what is left
Taking 30% off leaves 70%, so multiplying by 0.7 gets there in one step.
Two discounts do not add
20% off then another 10% off is not 30% off. The second is taken from the already reduced price.
What it actually is
0.8 × 0.9 = 0.72, so 28% off altogether, not 30%.
Taking a percent off
A 30% discount leaves 70%, so multiply by 0.7. A £60 coat becomes 60 × 0.7 = £42. Calculating the remaining percentage directly is faster than finding the discount and subtracting, and it makes fewer steps to get wrong.
Two discounts do not add
30% off then a further 20% off is not 50% off. It is 0.7 × 0.8 = 0.56, so 44% off. Successive percentages multiply, because the second applies to the already-reduced price. Shops rely on this looking better than it is.
Estimating a sale price
30% off £59.99 is roughly 30% off £60, which is £18 off, leaving about £42. Rounding to a friendly number gives a usable answer in seconds — often all you need to decide whether something is worth buying.
The answer must be smaller
A discounted price is always less than the original, and a price after tax is always more. Checking the direction catches the commonest error, which is multiplying by the percentage removed rather than the percentage remaining.
Step 2: Try It Yourself
Tap and try it out.
taken off and left to pay
15
35
the original
?
The hatched bar is the piece the story is asking for.
Step 3: Watch an Example
One step at a time.
Watch Leo Stack Two Discounts
A £100 coat is 20% off, then another 10% off at the till.
- Step 1
After 20% off, the price is 80% of 100, so £80.
Step 4: Your Turn
Practice makes it stick.
The Sale
Problem 1 of 2
£80 with 25% off. What do you pay, in pounds?
The Second Discount
Problem 2 of 2
£200, 50% off then 50% off again. What do you pay, in pounds?
Take It Off
1 of 4
£40 with 10% off. Pay in pounds?
2 of 4
£60 with 50% off. Pay in pounds?
3 of 4
What multiplier takes 40% off?
4 of 4
£100, 10% off then 10% off. Pay in pounds?
Step 5: Quick Check
Show what you know.
Question 1 of 1
£70 with 20% off. Pay in pounds?
What You Learned
- A discount is easier as what is left than as what is taken.
- Taking p% off means multiplying by 1 − p/100.
- Two discounts multiply; they never simply add.