Got It game for an adult and child. How can you play so that you know you will always win?
Can you explain the strategy for winning this game with any target?
Here is a chance to play a fractions version of the classic Countdown Game.
Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?
How many different differences can you make?
This article explains how to make your own magic square to mark a special occasion with the special date of your choice on the top line.
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?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
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.
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?
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?
By selecting digits for an addition grid, what targets can you make?
The letters in the following addition sum represent the digits 1 ... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
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?
Delight your friends with this cunning trick! Can you explain how it works?
Find the values of the nine letters in the sum: FOOT + BALL = GAME
Can you explain how this card trick works?
This Sudoku requires you to do some working backwards before working forwards.
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?
Different combinations of the weights available allow you to make different totals. Which totals can you make?
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?
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. . . .
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?
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
Make your own double-sided magic square. But can you complete both sides once you've made the pieces?
Replace each letter with a digit to make this addition correct.
Here is a chance to play a version of the classic Countdown Game.
Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?
There are nasty versions of this dice game but we'll start with the nice ones...
In the following sum the letters A, B, C, D, E and F stand for six distinct digits. Find all the ways of replacing the letters with digits so that the arithmetic is correct.
Investigate the different ways that fifteen schools could have given money in a charity fundraiser.
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.
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. . . .
Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
What happens when you add a three digit number to its reverse?
Use the differences to find the solution to this Sudoku.
Try out some calculations. Are you surprised by the results?
This Sudoku, based on differences. Using the one clue number can you find the solution?
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?
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. . . .
This article suggests some ways of making sense of calculations involving positive and negative numbers.
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?
What is the sum of all the digits in all the integers from one to one million?
A combination mechanism for a safe comprises thirty-two tumblers numbered from one to thirty-two in such a way that the numbers in each wheel total 132... Could you open the safe?
Choose two digits and arrange them to make two double-digit numbers. Now add your double-digit numbers. Now add your single digit numbers. Divide your double-digit answer by your single-digit answer. . . .
Find out about Magic Squares in this article written for students. Why are they magic?!
Choose any three by three square of dates on a calendar page...
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.