# Add and subtract numbers with up to three digits, using the efficient written methods of columnar addition and subtraction

New Maths Curriculum (2014): Year 3 objectives.

Column Subtraction using Place Value Counters

A good starting place for teaching column subtraction. Helps children to visualise the processes involved. Choose either expanded subtraction or column subtraction, with or without the need for borrowing.

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.

Expanded Addition using Place Value Counters

A step towards a more formal written method of columnar addition.

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.

Column Subtraction

Working towards an efficent method of column subtraction. Can be used to demonstate expanded subtraction (in which the numbers are partitioned) with or without the need for  borrowing.

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.

The next step towards an efficient formal method of column addition. Add the numbers starting with the least significant, then combine the partitioned result. Choice of 2-digit, 3-digit or 4-digit.

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 the partitioned numbers beginning with the largest. Choice of 2-digit, 3-digit or 4-digit numbers. An important conceptual step before a more formal method of column addition.

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.

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

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)