High Interest

10% of £12.80 =
20% of £12.80 =
30% of £12.80 =
40% of £12.80 =
50% of £12.80 =
60% of £12.80 =
70% of £12.80 =
80% of £12.80 =
90% of £12.80 =
100% of £12.80 =

10% of £12.80 =
5% of £12.80 =
2.5% of £12.80 =
1.25% of £12.80 =
0.625% of £12.80 =

No Calculator

Work out the answers to these calculations in your head or on paper.

There are many uses for percentages in real life. Finding a good personal loan for example requires an ability to calculate percentages. Interest is the extra amount you would have to pay back to the personal loan company for borrowing the money. On the other hand you can earn interest by depositing money in a bank or building society.

Globe of Flags

This activity is suitable for students of mathematics all around the world. Use the button below to change the currency symbol used to make it more relevant to your students. You may wish to choose an unfamiliar currency to extend your students' experience.

Globe of Flags

A Mathematics Lesson Starter Of The Day


Topics: Starter | Percentages

  • Fiona Ryan, Moonta Area School
  • I used this activity as a calculator skills activity for my Special Education class.
  • Transum,
  • This is your chance to get your students to practise the techniques they have learned. This really is a 'skill for life' activity and falls in the financial maths camp too. The ability to mentally calculate simple percentages is so useful but many students find their way through school without learning the tricks and tips. This starter needs discussing with the class when everyone has had a chance to do it. Strategies can be shared, misconceptions challenged and techniques refined.
  • Sandra C, London
  • I used this for a starter on one day, and on the following day, tackled percentages greater than 100% with a look at payday loans.
    We also looked at the difference between interest rate p.a. and APR.
  • Mrs Boyce,
  • School starts for us here is just two short weeks, so I am excited to make Transum a part of that school day beyond just the starters! I would like to say one more thing...I truly appreciate you making the little buttons at the bottom of the page that change pounds to dollars and such! It is fun to have the students see and learn the symbol, and talk about how it works, and how it compares to US currency. Then it leads to discussion about money conversion from country to country.

    Anyhow, I just wanted to take a moment and say well done! Your site is very well thought out. I appreciate your work very much.

How did you use this starter? Can you suggest how teachers could present or develop this resource? Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.
Click here to enter your comments.

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Excellent, I would like to see more like this
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This starter has scored a mean of 2.8 out of 5 based on 42 votes.

Previous Day | This starter is for 26 August | Next Day


% - This is the percent symbol.
Percent means 'out of 100'.

Find 50%:

As 50 is half of 100, then 50% means half. To find 50% of a quantity you need to halve (or divide by two). So 50% of 6 is 3.

Find 10%:

As 10 is one tenth of 100, then 10% means 'one tenth of'. To find 10% of a quantity you need to divide it by ten. So 10% of 800 is 80.

Find 25%:

As 25 is one quarter of 100, then 25% means 'one quarter of'. To find 25% of a quantity you need to divide it by four. So 25% of 20 is 5.

Another way of finding 25% of a quantity is first finding 50% then dividing the result by 2.

Find 33⅓%:

As 33 is one quarter of 100, then 33⅓% means 'one third of'. To find 33⅓% of a quantity you need to divide it by three. So 33⅓% of 30 is 10.

Find 1%:

As 1 is one hundredth of 100, then 1% means 'one hundredth of'. To find 1% of a quantity you need to divide it by 100. So 1% of 800 is 8.

Find other percentages:

Other percentages can be found by combining some of the techniques mentioned above. Here are some examples:

If you need to use a calculator to check your working. See Calculator Workout skill 3.


10% of £12.80 = £1.28
20% of £12.80 = £2.56
30% of £12.80 = £3.84
40% of £12.80 = £5.12
50% of £12.80 = £6.40
60% of £12.80 = £7.68
70% of £12.80 = £8.96
80% of £12.80 = £10.24
90% of £12.80 = £11.52
100% of £12.80 =£12.80
10% of £12.80 = £1.28 or 128p
5% of £12.80 = 64p
2.5% of £12.80 = 32p
1.25% of £12.80 = 16p
0.625% of £12.80 = 8p

Note to teacher: Doing this activity once with a class helps students develop strategies. It is only when they do this activity a second time that they will have the opportunity to practise those strategies. That is when the learning is consolidated. Click the button above to regenerate another version of this starter from random numbers.

Casio Classwiz Calculator

There is currently a lot of talk about this new calculator being the best in its price range for use in the Maths classroom. The new ClassWiz features a high-resolution display making it easier to view numerical formulas and symbols but it isn't a graphical calculator as such (it has the capacity to draw graphs on your smart phone or tablet, via a scannable QR code and an app).

As well as basic spreadsheet mode and an equation solving feature you also get the ability to solve quadratic, cubic or quartic polynomial inequalities and the answer is given just as it should be written down, using the correct inequality symbols!

This calculator has a high-performance processor and twice the memory of previous models ensuring speedy operation and superior computational power.more...

Online Maths Shop

Laptops In Lessons

Teacher, do your students have access to computers?
Do they have iPads or Laptops in Lessons?

Whether your students each have a TabletPC, a Surface or a Mac, this activity lends itself to eLearning (Engaged Learning).

Laptops In Lessons

Here a concise URL for a version of this page without the comments.


Here is a student interactive percentages exercise:


Student Activity


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