Can you explain how this card trick works?
Delight your friends with this cunning trick! Can you explain how
Four bags contain a large number of 1s, 3s, 5s and 7s. Pick any ten numbers from the bags above so that their total is 37.
For this challenge, you'll need to play Got It! Can you explain the strategy for winning this game with any target?
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
The idea of this game is to add or subtract the two numbers on the dice and cover the result on the grid, trying to get a line of three. Are there some numbers that are good to aim for?
Arrange the numbers 1 to 16 into a 4 by 4 array. Choose a number.
Cross out the numbers on the same row and column. Repeat this
process. Add up you four numbers. Why do they always add up to 34?
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
Different combinations of the weights available allow you to make different totals. Which totals can you make?
First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.
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?
An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.
The letters in the following addition sum represent the digits 1
... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
Do you notice anything about the solutions when you add and/or
subtract consecutive negative numbers?
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?
Find the values of the nine letters in the sum: FOOT + BALL = GAME
What are the missing numbers in the pyramids?
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
How many solutions can you find to this sum? Each of the different letters stands for a different number.
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
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.
This challenge extends the Plants investigation so now four or more children are involved.
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.
This addition sum uses all ten digits 0, 1, 2...9 exactly once.
Find the sum and show that the one you give is the only
Find out about Magic Squares in this article written for students. Why are they magic?!
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
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?
Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.
Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?
Make your own double-sided magic square. But can you complete both
sides once you've made the pieces?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10
Choose any three by three square of dates on a calendar page.
Circle any number on the top row, put a line through the other
numbers that are in the same row and column as your circled number.
Repeat. . . .
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?
Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
Use the numbers in the box below to make the base of a top-heavy
pyramid whose top number is 200.
Here is a chance to play a version of the classic Countdown Game.
Replace each letter with a digit to make this addition correct.
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?
Can you be the first to complete a row of three?
Can you put the numbers 1 to 8 into the circles so that the four
calculations are correct?
There are nasty versions of this dice game but we'll start with the nice ones...
This problem is based on a code using two different prime numbers
less than 10. You'll need to multiply them together and shift the
alphabet forwards by the result. Can you decipher the code?
This is an adding game for two players.
Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.
Place the numbers 1 to 10 in the circles so that each number is the
difference between the two numbers just below it.
A game for 2 people using a pack of cards Turn over 2 cards and try
to make an odd number or a multiple of 3.
If you have only four weights, where could you place them in order
to balance this equaliser?
Place the digits 1 to 9 into the circles so that each side of the
triangle adds to the same total.
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.
Exactly 195 digits have been used to number the pages in a book.
How many pages does the book have?