# Solve simple one-step problems with addition and subtraction: using concrete objects and pictorial representations, including those involving numbers, quantities and measures; applying their increasing knowledge of mental and written methods

New Maths Curriculum (2014): Year 2 objectives.

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.

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.

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.

Difference using a marked number line

Count on from the smaller number to the larger. As numbers are added to the balance scale they are also shown on the number line. Children should be encouraged to use their knowledge of number bonds to develop efficient mental methods.

Levels include counting up to 10, 20, 50 or 100, finding the difference between 2-digit numbers and decimals.

Different ways to pay

Find different ways to make the same amount of money. Drag the coins into the till to make a given amount. Includes a choice of international currencies.

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.

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.

ITP Number Facts

View full screen in your browser.  This ITP displays up to 20 coloured counters and the corresponding addition sentence. The number of counters you select, appear on the screen in purple. Click on any counter to change its colour, the number sentence also changes. To hide and reveal the number sentence, click on the box with the question marks. You can replace a number in the number sentence with a question mark by clicking on the number, and drag counters around the screen to form groups. Addition can be changed to subtraction by clicking on the addition sign in the box. Counters can be dragged into the displayed box, which you can make opaque to hide the counters.
The ITP can be used to model addition by combining and counting, and subtraction by partitioning and taking away. The hide and reveal options allow you to pose questions with unknown numbers in different positions in the number sentence. Partitioning counters in different ways helps children to identify all sums and differences of numbers to 20.

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

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.