# Use knowledge of addition and subtraction facts and place value to derive sums and differences of pairs of multiples of 10, 100 or 1000

Addition - Crystal Crash

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.

 1) Add numbers up to 10 (Y1) 6) Add three one-digit numbers (Y2) 11) Add a three-digit number and ones (Y3) 16) Add combinations of two and three digit numbers (y4) 2) Add numbers up to 20 (Y1) 7) Addition pairs that make 100 (multiples of 10) (Y3) 12) Add a three-digit number and tens (Y3) 17) Add combinations of decimals (1dp) (Y4) 3) Add a two-digit number and ones (Y2) 8) Addition pairs that make 100 (multiples of 5) (Y3) 13) Add a three-digit number and hundreds (Y3) 18) Add pairs of decimals (2dp) that make 1 (Y5 & Y6) 4) Add a two-digit number and tens (Y2) 9) Addition pairs that make 100 (Y3 & Y4) 14) Add pairs of decimals (1dp) that make 1 (Y4 & Y5) 19) Add combinations of three-digit numbers (Y5 & Y6) 5) Add two two-digit numbers (Y2) 10) Add pairs that make 1000 (multiples of 100) (Y3 & Y4) 15) Add pairs of decimals (1dp) that make 10 (Y4 & Y5) 20) Add combinations of decimals (2dp) (Y5 & Y6)
KS2 Maths Invaders

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.

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).

For more addition and subtraction resources click here.

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.

For more multiplication and division resources click here.

For more addition and subtraction resources click here.

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.

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.

For more addition and subtraction resources click here.

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.

For more addition and subtraction resources click here.

For more multiplication and division resources click here.

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)