Module 3 Calculating
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Can I calculate simple percentages of whole numbers or quantities?

Example review questions

  • Find 10% of £40.
  • What is 25% of 50?
  • What is 99% of 200?
  • Use a calculator to find 20% of £362.
    Explain your method.
  • Is 75% of 200 ml more or less than 25% of 500 ml? How do you know?
  • There is 50% off all prices in a sale. An MP3 player costs £45 in the sale. How much was it before the sale?
  • The full price of a camera is £399. How much would it cost in the sale?

Teaching guidance

This teaching guidance document suggests some of the key vocabulary, models, images and practical equipment that children should experience and be able to use. It also includes some teaching tips to provide a few starting points for ways of supporting children with this area of mathematics.

PDF file Can I calculate simple percentages of whole numbers or quantities? - teaching guidance | 60KB new window

Consolidation and practice

These resources are to support children in guided or independent work.

XLS file Fraction and percentage equivalence | 33KB new window

DOC file Fraction and percentage equivalence guide | 192KB new window

XLS file Calculate percentages | 137KB new window

PDF file Springboard 6, Lesson 9 Calculate simple percentages of whole-number quantities | 41KB new window

PDF file Springboard 7, Unit 13, Section 2 Fractions and percentages | 1.3MB new window

Calculating angles

itp_calculating_angles.png

This interactive teaching program (ITP) is an ICT-based tool to support the exploration of angles. Calculating angles ITP allows the child or teacher to represent single or multiple shapes rotated around a central point in one, two or four quadrants. The size of angles can be estimated or calculated and confirmed using the on-screen protractor or reveal function.

Polygon

itp_polygons.png

This interactive teaching program (ITP) is an ICT-based tool to support the exploration of shape, space and measure. Polygon ITP allows the child or teacher to represent regular polygons with three to ten sides. The ITP can then be used to explore the properties of regular and irregular shapes by dragging vertices and creating additional vertices. The ITP includes an on-screen protractor and ruler.

Fixing points

itp_fixing_points.png

This interactive teaching program (ITP) is an ICT-based tool to support the exploration of shape and space. Fixing points ITP allows the child or teacher to create one or more shapes by connecting a number of vertices on a grid. Angles can be estimated and measured, and the effect of moving different vertices can be explored.

Opportunities to use and apply

Possible contexts include:

  • money, e.g. The agent’s fee for selling a house is 5%. Calculate the fee on a house sold for £80 000. How did you calculate the fee?
  • looking for examples of and asking questions about percentages in everyday life, e.g. Use local newspaper advertisements to work out how much money you are saving after a percentage discount.
  • data handling, e.g. collect data from 36 people, use a data-handling software package to present this as a pie chart and respond to questions about the percentage represented by each section of the pie chart.
 

Confirming learning

Ask probing questions such as:

  • Kate says: 'To find 10% of an amount, you divide it by 10. So to find 20% of an amount, you divide it by 20.' Is Kate correct? How do you know?
  • What calculations would you do to find 15% of £150?
  • When finding percentages of quantities, what percentage do you usually start from? How does this percentage help you work out other percentages?
  • Tell me two amounts where one is 25% of the other. Can you think of an example where one of the amounts is 80? How many possibilities are there?