A 20% tip on £40 is 20% of 40, which is £8, added on to give £48.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
The two-step way
Find the percent, then add it to the original.
The one-step way
The total is 100% + 20% = 120% of the original, so multiply by 1.2 straight away.
Both are right
The multiplier is faster and matters later, because it can be undone by dividing.
Adding a percent on top
A £40 meal with a 15% tip costs 40 + 6 = £46. Or multiply directly: 40 × 1.15 = 46. The multiplier method is one step instead of two and is much quicker when several items are involved.
Working out a tip mentally
10% is the bill with the digits shifted one place right. Half of that is 5%. So 15% is 10% plus 5%: for £40, that is 4 + 2 = £6. Building from 10% is how most people do this in a restaurant, and it is genuinely fast.
Markup is the same calculation
A shop buying at £30 and marking up 40% sells at 30 × 1.4 = £42. Tax, tips, markup, service charges and commission are all one percentage increase, differing only in what the money is for.
Does the order matter?
Applying tax then a tip, or a tip then tax, gives the same total, because multiplying by 1.2 and 1.15 in either order gives the same product. Multiplication is commutative — a property that turns out to have real financial consequences.
Step 2: Try It Yourself
The original amount and the part added on top.
original and added on
40
8
the total
?
The hatched bar is the piece the story is asking for.
Step 3: Watch an Example
One step at a time.
Watch Ana Add a Tip
A meal costs £40 and Ana leaves a 15% tip.
- Step 1
She finds 10% by moving the digits: £4.
Step 4: Your Turn
Practice makes it stick.
The Bill
Problem 1 of 2
A £60 bill with a 10% tip. What is the total, in pounds?
The Tax
Problem 2 of 2
A £200 item with 20% tax added. What is the total, in pounds?
Add It On
1 of 4
£50 with 10% added. Total in pounds?
2 of 4
£80 with 25% added. Total in pounds?
3 of 4
What multiplier adds 30%?
4 of 4
£120 with 5% added. Total in pounds?
Step 5: Quick Check
Show what you know.
Question 1 of 1
£90 with 20% added. Total in pounds?
What You Learned
- A tip, a tax, and a markup are all a percent of the original added on.
- Adding p% means multiplying by 1 + p/100.
- The multiplier does it in one step and can be undone later.