Other tags that relate to Mathland Election
Place value. Combinatorics. Games. Ratio and proportion. Comparing and ordering numbers. Percentages. Fractions. Addition & subtraction. Mental calculation strategies. Estimating and approximating.There are 73 results
Broad Topics > Calculations and Numerical Methods > Addition & subtraction
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?
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...
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.
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?
Difference Sudoku
Age 14 to 16
Challenge Level
Use the differences to find the solution to this Sudoku.
Countdown
Age 7 to 14
Challenge Level
Here is a chance to play a version of the classic Countdown Game.
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?
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?
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?
3388
Age 11 to 14
Challenge Level
Using some or all of the operations of addition, subtraction, multiplication and division and using the digits 3, 3, 8 and 8 each once and only once make an expression equal to 24.
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?
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.
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.
Largest Number
Age 11 to 14
Challenge Level
What is the largest number you can make using the three digits 2, 3 and 4 in any way you like, using any operations you like? You can only use each digit once.
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?
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?
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.
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.
Weights
Age 11 to 14
Challenge Level
Different combinations of the weights available allow you to make different totals. Which totals can you make?
Pair Sums
Age 11 to 14
Challenge Level
Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?
Digit Sum
Age 14 to 16 Short
Challenge Level
What is the sum of all the digits in all the integers from one to one million?
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?
Football Sum
Age 11 to 14
Challenge Level
Find the values of the nine letters in the sum: FOOT + BALL = GAME
Cayley
Age 11 to 14
Challenge Level
The letters in the following addition sum represent the digits 1 ... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
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.
Add to 200
Age 11 to 14
Challenge Level
By selecting digits for an addition grid, what targets can you make?
An Introduction to Magic Squares
Age 7 to 16
Find out about Magic Squares in this article written for students. Why are they magic?!
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.
As Easy as 1,2,3
Age 11 to 14
Challenge Level
When I type a sequence of letters my calculator gives the product of all the numbers in the corresponding memories. What numbers should I store so that when I type 'ONE' it returns 1, and when I type. . . .
Pairs
Age 11 to 14
Challenge Level
Ann thought of 5 numbers and told Bob all the sums that could be made by adding the numbers in pairs. The list of sums is 6, 7, 8, 8, 9, 9, 10,10, 11, 12. Help Bob to find out which numbers Ann was. . . .
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. . . .
Alphabetti Sudoku
Age 11 to 16
Challenge Level
This Sudoku requires you to do some working backwards before working forwards.
Forwards Add Backwards
Age 11 to 14
Challenge Level
What happens when you add a three digit number to its reverse?
Subtraction Surprise
Age 7 to 14
Challenge Level
Try out some calculations. Are you surprised by the results?
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?
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?
Countdown Fractions
Age 11 to 16
Challenge Level
Here is a chance to play a fractions version of the classic Countdown Game.
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.
Adding All Nine
Age 11 to 14
Challenge Level
Make a set of numbers that use all the digits from 1 to 9, once and once only. Add them up. The result is divisible by 9. Add each of the digits in the new number. What is their sum? Now try some. . . .
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?
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.
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?
Have You Got It?
Age 11 to 14
Challenge Level
Can you explain the strategy for winning this game with any target?
Cunning Card Trick
Age 11 to 14
Challenge Level
Delight your friends with this cunning trick! Can you explain how it works?
NRICH is part of the family of activities in the Millennium Mathematics Project.