'Mental addition and subtraction' tutor notes

This module can be used as a starting point for: learning different methods of mental addition and subtraction.

Please let us know what you think of the factsheets, worksheets, quiz and games at skillswise.feedback@bbc.co.uk

How does this tie in with the new curriculums?

• England
  N1/E3.2 - add and subtract using three-digit whole numbers.
  N1/E3.3 - recall addition and subtraction facts to 20.
  N1/L1.8 - approximate by rounding.
  
• Wales As England
• Northern Ireland As England
• Scotland
  See www.aloscotland.com for details of the Scottish curriculum.

In the Skillswise module you'll find:

Mental addition and subtraction factsheets
There are ten sheets in this section which can be printed out and kept.

• Factsheet 1 - SHARED - An overview of 5 methods for mental addition and subtraction.
• Factsheet 2 - Reminders to help the students with mental addition and subtraction.
• Factsheet 3 - Method 1 - splitting up numbers.
• Factsheet 4 - Method 2 - hundreds, tens and units.
• Factsheet 5 - Method 3 - rounding (addition).
• Factsheet 6 - Method 3 - rounding (subtraction).
• Factsheet 7 - Method 4 - empty number line.
• Factsheet 8 - Method 5 - doubling.
• Factsheet 9 - Key words for mental addition.
• Factsheet 10 - Key words for mental subtraction.

Mental addition and subtraction games
There are seven games for practising mental addition and subtraction.

Game 1: The Change Game - no timer

In this game you are working on a till serving customers. You have 5 customers to serve. The till shows the cost of the items the customer is buying, and the customers hand appears with a note, £5, £10 or £20. You must give the correct change, by dragging conis and notes from the cash drawer into the customers hand. You have 3 chances each time.

There are 3 levels to choose from.
Level 1: Customer pays with a £5 or £10 note. Giving correct change requires whole pounds and 50p pieces only.
Level 2: Customer pays with a £5 or £10 note. Giving correct change requires whole pounds and multiples of 10p only.
Level 3: Customer pays with a £5, £10 or £20 note. Any price can come up so all coins and notes may be needed in giving change.

This game has sound effects. (Listen out for when you give too much change!)

Game 2: The Change Game - with timer

This is the same game but with a time limit. The object is to serve as many customerse as you can before the time runs out.

Game 3 and Game 4: Mental Maths Fridge Magnet Games

In these games the learner can practice mental addition and subtraction skills by filling blanks in sums written out in fridge magnets.

At the start of the game, the learner can choose whether to answer questions by finding the answer or filling a blank in the question (eg. 35 - ? = 20). They can also choose whether to have a time limit (60 seconds) on each question. At the end they are given a score out of 10.

With a score of 8 or more a bonus screen is available, on which there is a random selection of fridge magnet letters to re-arrange and play about with.

Game 5: Bargain Hunt
This is a mental addition game which is based on the BBC Bargain Hunt programme and features David Dickinson. The student has to add up the prices of the antiques on the cards. The student can select to add up two or three numbers. There are 3 levels, A, B and C with A being the easiest and C the hardest. At level A the numbers are easier to add up as the units don't carry over and there is more time to calculate the sum. At level C units and tens carry over and there is less time to calculate the sum.

Game 6 and Game 7: Mental Maths Conveyor Belt Games

In these games, the learner can practice mental addition and subtraction skills by answering questions relating to items which appear on a conveyor belt.

At the start of the game, the learner can choose whether to answer questions by clicking on one of three choices, or by typing in their answers and clicking 'check' or hitting the return key. If they answer any question incorrectly, they get the choice of a second chance or just to see the correct answer. At the end they are given a summary of the questions, the answers they gave and their score.

If the learner answers more than 8 out of 10 questions correctly, they will be given the option of a bonus 'tennis' game, which is played using the mouse.

TOP TIP! To see any of the games completely full screen, press the F11 key on the keyboard. This takes away the distraction of the top browser bar. To bring the browser bar back, just press F11 again!

Mental addition and subtraction quiz
The learner can choose their level. Level A is the easiest, level C the hardest.
Students can print out a certificate if they score 50% or more in the quiz. This will appear as a link on the results page - click on the link and the certificate will appear in a new window. Once printed students can write their name on the certificate.

Mental addition and subtraction worksheets
There are five printable worksheets in this section, for learners to carry on the work done online.

• Worksheet 1 - Some practise for method 1 - splitting up numbers.
• Worksheet 2 - Identify which numbers add up to a certain amount, using hundreds, tens and units.
• Worksheet 3 - Some sums to practise addition and subtraction by rounding.
• Worksheet 4 - An empty number line worksheet.
• Worksheet 5 - A worksheet to practise doubling.

Technical help:

To get the most out of this topic area you need the following 'plug-ins':

• Flash
  The game in this topic section uses Flash. This is free to download and should only take a few minutes. You can follow the BBC WebWise instructions to download it to your machine.
  Find out more.

If you don't have Flash the same learning points are covered in the quiz and in the worksheets and factsheets.
If you are new to the web, why not try the BBC WebWise online course, Becoming WebWise? It's free, you can do it in your own time from any computer and it will take you through everything you need to know to use the web successfully in your teaching.
Get WebWise.

You can find out more about the technical requirements for Skillswise in our Help - Technical Information section.

Taking it further:

Here are a few suggestions of other places on the web that you might find useful resources that you can adapt for teaching mental addition and subtraction.

• BBC KS2 Bitesize Maths
  Bitesize is aimed at children at the end of Key Stage 2, but it still has useful activities you can try with your students.
• AAA Math - addition
• AAA Math - subtraction
  An American site containing many pages demonstrating different addition and subtraction skills, with interactive activities and games.

Please note that the BBC is not responsible for the content of other websites.

Don't forget to visit Lesson plans and Teaching inspirations for more ideas for teaching mental maths.

Do you know of any great online resources for practising mental maths? Tell us about them!