# Add or subtract mentally a one-digit number or a multiple of 10 to or from any two-digit number; use practical and informal written methods to add and subtract two-digit numbers

Shoot the spaceship with the correct answer and dodge the incoming fire. A fun game to practise a wide range of key mathematical skills.

There are over a hundred carefully differentiated levels linked to objectives from the new maths curriculum. The game can be used to teach: Multiplication, Addition, Reading Numbers, Subtraction, Fractions of Numbers, Roman Numerals, Rounding Numbers, Division, Converting Fractions to Decimals, Converting Fractions to Percentages, Telling the Time in Words, Recognising Multiples, Factors, Prime, Square and Cube Numbers, and Simplifying Fractions. A full list of levels is below. This game is also available as an iOS and Android app.

Missing Symbols

Drag the symbols to the correct position to make the number sentence correct. Lots of levels to play. See if you can improve your score over time.

This game is now part of the 'Calculations' collection, which includes the following 17 games and resources: Column Addition, Expanded Addition, Expanded Addition - Place Value Counters, Number Bonds(2), Addition - Digit Drag, Missing Symbols, Column Subtraction, Column Subtraction using Place Value Counters, Counting on to find difference on a beadstring, Multiplication Grid Method, Multiplication Written Method, Ratio and Scaling Numbers, Representing Multiplication, Division by Chunking Up, Division by Chunking Down, Formal Written Division - Round Up or Down?, Short Division Writen Formal Method.

The Calculations app is available on Google Play and the App Store.

Monty's Maths Wall

Use the arrow keys to guide your bricks and destroy the wall.

A great game for practising a wide range of mathematical skills. Levels are based on objectives from the new maths curriculum from Year 1 to Year 6. Topics include: multiplication, addition, reading numbers, subtraction, fractions of numbers, Roman numerals, division, converting fractions to decimals and percentages and simplifying fractions.

You can choose to play a single level, a selection of levels, or choose all the objectives from a year group (within the same topic). There is a full list of levels below.

This game is available on both Google Play and the App Store. A free version of the app is available with just the multiplication levels.

A fun game to practise mental addition skills. The game was designed to cover all the mental addition objectives in the new math curriculum. You can choose one objective, or choose all the objectives for a year group.

This game, together with all the other crystal crash games, is available as a single iPad or Android app.

Answer addition and subtraction questions to arrange the dominoes in the correct order as quickly as possible. Lots of choice over level including; add and/or subtract within 20, 50, 100, using decimals or with negative numbers.

Bubble Pop - Number Bonds

A great way to practise number bonds and mental addition. Levels include: number bonds to 10, 20, 50 and 100 as well as addition pairs with a total of up to 20, 50 or 100. Look at the target at the top of the screen and then aim your bubble to make that target.

As a teacher I know how important it is that children know their number bonds (pairs of numbers that add up to 10, 20, 50 or 100), and can add quickly mentally. Repetition is essential in learning number bonds. This game is designed to make the process fun.

Children have to aim their bubble to make a given sum. As they progress the levels get harder; they have less time, or less bubbles to shoot. Each correct answer is accompanied by an image to reinforce the number bond they have found.

This game is available on iPad, iPod and iPhone, as well as on android phones and tablets.

Balancing Sums

An excellent tool for reinforcing an understanding of the role of the equals sign. Choose one objective, or many. You can choose all the objectives for a single year group (or multiple year groups). You can also choose to balance between different types of calculations (eg addition and multiplication).

Subtraction - Crystal Crash

The game was designed to cover all the mental subtraction objectives in the new math curriculum. You can choose one objective, or choose all the objectives for a year group.

This game, together with all the other crystal crash games, is available as a single iPad or Android app.

 1) Subtract numbers from up to 10 (Y1) 6) Subtract from 100 (multiples of 10) (Y3) 11) Subtract tens from a three-digit number (Y3) 16) Subtract combinations of decimals (1dp) (Y4) 2) Subtract numbers from up to 20 (Y1) 7)Subtract from 100 (multiples of 5) (Y3) 12) Subtract hundreds from a three-digit number (Y3) 17) Subtract a decimal (2dp) from 1  (Y5 & Y6) 3) Subtract ones from a two-digit number (Y2) 8) Subtract from 100 (Y3 & Y4) 13) Subtract a decimal (1dp) from 1 (Y4 & Y5) 18) Subtract combinations of three-digit numbers (Y5 & Y6) 4) Subtract tens from a two-digit number (Y2) 9) Subtract from 1000 (multiples of 100) (Y3 & Y4) 14) Subtract a decimal (1dp) from 10 (Y4 & Y5) 19) Subtract combinations of decimals (2dp) (Y5 & Y6) 5) Subtract a two-digit number from a two-digit number (Y2) 10) Subtract ones from a three-digit number(Y3) 15) Subtract two-digit numbers from three-digit numbers (y4)
Counting on to find a difference - beadstrings

I designed this activity to help children to visualise small differences between 2-digit numbers by bridging through multiples of 10. It can also be used to explore links between addition and subtraction and to begin to find differences using a number line.

This game is now part of the 'Calculations' collection, which includes the following 17 games and resources: Column Addition, Expanded Addition, Expanded Addition - Place Value Counters, Number Bonds(2), Addition - Digit Drag, Missing Symbols, Column Subtraction, Column Subtraction using Place Value Counters, Counting on to find difference on a beadstring, Multiplication Grid Method, Multiplication Written Method, Ratio and Scaling Numbers, Representing Multiplication, Division by Chunking Up, Division by Chunking Down, Formal Written Division - Round Up or Down?, Short Division Writen Formal Method.

The Calculations app is available on Google Play (£1.25) and will be available in the App Store in July.

Add and Subtract on a Number Line

Add and subtract near multiples on a number line. Develop mental methods of addition and subtraction by adding and subtracting a multiple of 10 or 100, and then adjusting. For example add 29 by adding 30 and then subtracting 1.

Number Bonds (2)

Designed to help children to visualise and understand number bonds to 20, 50 and 100. Numbers are represented on a number line and using base-ten blocks.

This game is now part of the 'Calculations' collection, which includes the following 17 games and resources: Column Addition, Expanded Addition, Expanded Addition - Place Value Counters, Number Bonds(2), Addition - Digit Drag, Missing Symbols, Column Subtraction, Column Subtraction using Place Value Counters, Counting on to find difference on a beadstring, Multiplication Grid Method, Multiplication Written Method, Ratio and Scaling Numbers, Representing Multiplication, Division by Chunking Up, Division by Chunking Down, Formal Written Division - Round Up or Down?, Short Division Writen Formal Method.

The Calculations app is available on Google Play and the App Store.

Drag the digits to make a given sum. Lots of choice over level. A great starter activity for discussions on place value, mental methods of calculations and problem solving.

Number Bonds

October 2012: New game added in which number bonds are represented visually using base-ten blocks and a number line.

Find pairs of numbers with a given total. Play against the clock.

Balance scales - add, move or remove a weight

Balance the scales by adding, moving or removing a weight. A great mental starter to develop addition and subtraction skills.

Number Facts Beat The Clock

Score as many points as you can before the time runs out. A number of levels including addition, subtraction, multiplication, division and matching fractions and decimals.

*Updated 30th May 2013 - choose multiple objectives, or objectives grouped by national curriculum level. The game also now includes a scoreboard. An iPad version is also available.

Ordering Calculations

Order the calulations from those with the least value to the greatest. Lots of levels, including; addition pairs to 20, addition pairs to 100, addition and subtraction of multiples of 10, and multiplication of numbers up to 10.

Solve 1 Step Money Problems

Read and interpret a word problem involving addition or subtraction and then solve.

Card Game - Matching Pairs

Match the pairs of cards with the same value. A great game to play as a mental starter. Over 50 levels to play including; addition, subtraction, multiplication, division, matching fractions and decimals and converting between measurements.

Sequences

Find the correct number in a sequence. Lots of choice over level, count forwards or back, count in whole numbers, multiples of 10, multiples of 100, decimals and fractions.

Balancing Scales g and kg

Add weights to either pan until they are balanced. Can be used to teach addition, subtraction, partitioning, and mass, as well as developing an understanding of the equals sign.

Choose from grams, whole kilograms or kilograms with either 1 or 2 decimal places.

I have created my own version of this ITP which allows you to find the difference between two numbers and shows this on a number line.

View full screen in your browser.  This ITP simulates a 100-bead string. You can move all the beads to the right of the string and move individual or groups of beads to the left side of the string by clicking on selected beads.
The controls also allow you to move 1 or 10 beads to the left or right of the string to show addition and subtraction. This ITP can be used to model different counting and calculation strategies.

This resource is freely available to download from the archived Primary Framework site.

ITP Difference

I have created my own version of this ITP which allows you to find the difference between two 2-digit numbers and shows this on a number line.

View full screen in your browser.  This ITP allows you to compare two rows of beads and to analyse the calculations they can represent. It can be used to promote the language of addition and subtraction, particularly the interpretation of difference. The ITP operates as a series of animations which show how the rows of beads can be represented by two number lines and then as a single number line with the difference indicated by a ‘jump’.

This resource is freely available to download from the archived Primary Framework site.