Show that addition of two numbers can be done in any order (commutative) and subtraction of one number from another cannot

New Maths Curriculum (2014): Year 2 objectives.

 
Inverse Operations - Addition and Subtraction Inverse Operations - Addition and Subtraction

I designed this resource to help children to visualise the relationship between addition and subtraction. They can then use this relationship to solve missing number problems. There are a wide range of levels, from adding within 20 to using a calculator to add and subtract 5 digit numbers and decimals.

Addition - Crystal Crash 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)

Subtraction - Crystal Crash 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)