Resources tagged with: Addition & subtraction

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There are 73 NRICH Mathematical resources connected to Addition & subtraction, you may find related items under Calculations and Numerical Methods.

Broad Topics > Calculations and Numerical Methods > Addition & subtraction

Can You Make 100?

Age 11 to 14
Challenge Level

How many ways can you find to put in operation signs (+ - x ÷) to make 100?

Subtraction Surprise

Age 7 to 14
Challenge Level

Try out some calculations. Are you surprised by the results?

Making Sense of Positives and Negatives

Age 11 to 14

This article suggests some ways of making sense of calculations involving positive and negative numbers.

Nice or Nasty

Age 7 to 14
Challenge Level

There are nasty versions of this dice game but we'll start with the nice ones...

Countdown Fractions

Age 11 to 16
Challenge Level

Here is a chance to play a fractions version of the classic Countdown Game.

Countdown

Age 7 to 14
Challenge Level

Here is a chance to play a version of the classic Countdown Game.

Crossed Ends

Age 11 to 14
Challenge Level

Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?

Weights

Age 11 to 14
Challenge Level

Different combinations of the weights available allow you to make different totals. Which totals can you make?

Adding and Subtracting Positive and Negative Numbers

Age 11 to 14

How can we help students make sense of addition and subtraction of negative numbers?

Consecutive Negative Numbers

Age 11 to 14
Challenge Level

Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

Connect Three

Age 11 to 16
Challenge Level

In this game the winner is the first to complete a row of three. Are some squares easier to land on than others?

Difference Sudoku

Age 14 to 16
Challenge Level

Use the differences to find the solution to this Sudoku.

Cunning Card Trick

Age 11 to 14
Challenge Level

Delight your friends with this cunning trick! Can you explain how it works?

Diagonal Sums

Age 7 to 14
Challenge Level

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?

Consecutive Seven

Age 11 to 14
Challenge Level

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?

Number Pyramids

Age 11 to 14
Challenge Level

Try entering different sets of numbers in the number pyramids. How does the total at the top change?

Amazing Card Trick

Age 11 to 14
Challenge Level

How is it possible to predict the card?

Cinema Problem

Age 11 to 14
Challenge Level

A cinema has 100 seats. Show how it is possible to sell exactly 100 tickets and take exactly £100 if the prices are £10 for adults, 50p for pensioners and 10p for children.

Cubes Within Cubes

Age 7 to 14
Challenge Level

We start with one yellow cube and build around it to make a 3x3x3 cube with red cubes. Then we build around that red cube with blue cubes and so on. How many cubes of each colour have we used?

Number Daisy

Age 11 to 14
Challenge Level

Can you find six numbers to go in the Daisy from which you can make all the numbers from 1 to a number bigger than 25?

Two and Two

Age 11 to 16
Challenge Level

How many solutions can you find to this sum? Each of the different letters stands for a different number.

Summing Consecutive Numbers

Age 11 to 14
Challenge Level

15 = 7 + 8 and 10 = 1 + 2 + 3 + 4. Can you say which numbers can be expressed as the sum of two or more consecutive integers?

Plants

Age 5 to 14
Challenge Level

Three children are going to buy some plants for their birthdays. They will plant them within circular paths. How could they do this?

Consecutive Numbers

Age 7 to 14
Challenge Level

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

Charitable Pennies

Age 7 to 14
Challenge Level

Investigate the different ways that fifteen schools could have given money in a charity fundraiser.

Forwards Add Backwards

Age 11 to 14
Challenge Level

What happens when you add a three digit number to its reverse?

Add to 200

Age 11 to 14
Challenge Level

By selecting digits for an addition grid, what targets can you make?

Cryptarithms

Age 11 to 14
Challenge Level

Can you crack these cryptarithms?

Making a Difference

Age 11 to 14
Challenge Level

How many different differences can you make?

Got it for Two

Age 7 to 14
Challenge Level

Got It game for an adult and child. How can you play so that you know you will always win?

Nice or Nasty for Two

Age 7 to 14
Challenge Level

Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.

Up, Down, Flying Around

Age 11 to 14
Challenge Level

Play this game to learn about adding and subtracting positive and negative numbers

Magic Letters

Age 11 to 14
Challenge Level

Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?

More Plant Spaces

Age 7 to 14
Challenge Level

This challenging activity involves finding different ways to distribute fifteen items among four sets, when the sets must include three, four, five and six items.

More Children and Plants

Age 7 to 14
Challenge Level

This challenge extends the Plants investigation so now four or more children are involved.

Twenty20

Age 7 to 16
Challenge Level

Fancy a game of cricket? Here is a mathematical version you can play indoors without breaking any windows.

Escape from the Castle

Age 7 to 14
Challenge Level

Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?

2010: A Year of Investigations

Age 5 to 14

This article for teachers suggests ideas for activities built around 10 and 2010.

Pole Star Sudoku 2

Age 11 to 16
Challenge Level

This Sudoku, based on differences. Using the one clue number can you find the solution?

Alphabetti Sudoku

Age 11 to 16
Challenge Level

This Sudoku requires you to do some working backwards before working forwards.

Constellation Sudoku

Age 14 to 18
Challenge Level

Special clue numbers related to the difference between numbers in two adjacent cells and values of the stars in the "constellation" make this a doubly interesting problem.

Making Maths: Double-sided Magic Square

Age 7 to 14
Challenge Level

Make your own double-sided magic square. But can you complete both sides once you've made the pieces?

Multiply the Addition Square

Age 11 to 14
Challenge Level

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?

Mathematical Symbols

Age 5 to 14

A brief article written for pupils about mathematical symbols.

An Introduction to Magic Squares

Age 7 to 16

Find out about Magic Squares in this article written for students. Why are they magic?!

Got it Article

Age 7 to 14

This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.

Clocked

Age 11 to 14
Challenge Level

Is it possible to rearrange the numbers 1,2......12 around a clock face in such a way that every two numbers in adjacent positions differ by any of 3, 4 or 5 hours?

Jugs of Wine

Age 11 to 14
Challenge Level

You have four jugs of 9, 7, 4 and 2 litres capacity. The 9 litre jug is full of wine, the others are empty. Can you divide the wine into three equal quantities?

Arrange the Digits

Age 11 to 14
Challenge Level

Can you arrange the digits 1,2,3,4,5,6,7,8,9 into three 3-digit numbers such that their total is close to 1500?

Postage

Age 14 to 16
Challenge Level

The country Sixtania prints postage stamps with only three values 6 lucres, 10 lucres and 15 lucres (where the currency is in lucres).Which values cannot be made up with combinations of these postage. . . .