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There are 336 NRICH Mathematical resources connected to Addition and subtraction, you may find related items under Calculations and numerical methods.
Broad Topics > Calculations and numerical methods > Addition and subtractionIf you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.
You are organising a school trip and you need to write a letter to parents to let them know about the day. Use the cards to gather all the information you need.
This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask?
This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.
This activity is best done with a whole class or in a large group. Can you match the cards? What happens when you add pairs of the numbers together?
Can you each work out the number on your card? What do you notice? How could you sort the cards?
There are nasty versions of this dice game but we'll start with the nice ones...
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
Here is a chance to play a version of the classic Countdown Game.
Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.
A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?
Different combinations of the weights available allow you to make different totals. Which totals can you make?
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.
How can we help students make sense of addition and subtraction of negative numbers?
The picture shows a lighthouse and some underwater creatures. Can you work out the distances between some of the different creatures?
In this game, you can add, subtract, multiply or divide the numbers on the dice. Which will you do so that you get to the end of the number line first?
Can you use the numbers on the dice to reach your end of the number line before your partner beats you?
Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?
Add or subtract the two numbers on the spinners and try to complete a row of three. Are there some numbers that are good to aim for?
In this game the winner is the first to complete a row of three. Are some squares easier to land on than others?
Use the differences to find the solution to this Sudoku.
These caterpillars have 16 parts. What different shapes do they make if each part lies in the small squares of a 4 by 4 square?
A resource to try once children are familiar with number lines, and they have begun to use them for addition. It could be a good way to talk about subtraction. Leah and Tom each have a number line. Can you work out where their counters will land?
Annie and Ben are playing a game with a calculator. What was Annie's secret number?
Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?
Delight your friends with this cunning trick! Can you explain how it works?
Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?
Can you hang weights in the right place to make the the number balance balanced?
Have a go at this game which involves throwing two dice and adding their totals. Where should you place your counters to be more likely to win?
In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.
These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it. Can you work out the missing numbers?
Here are some rods that are different colours. How could I make a yellow rod using white and red rods?
Can you arrange these numbers into 7 subsets, each of three numbers, so that when the numbers in each are added together, they make seven consecutive numbers?
Tim had nine cards each with a different number from 1 to 9 on it. How could he have put them into three piles so that the total in each pile was 15?
Use these head, body and leg pieces to make Robot Monsters which are different heights.
As you come down the ladders of the Tall Tower you collect useful spells. Which way should you go to collect the most spells?
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?
Find out what a Deca Tree is and then work out how many leaves there will be after the woodcutter has cut off a trunk, a branch, a twig and a leaf.