This cube has ink on each face which leaves marks on paper as it is rolled. Can you work out what is on each face and the route it has taken?
Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?
Can you arrange the digits 1, 1, 2, 2, 3 and 3 to make a Number Sandwich?
Find the values of the nine letters in the sum: FOOT + BALL = GAME
An extra constraint means this Sudoku requires you to think in diagonals as well as horizontal and vertical lines and boxes of nine.
Each clue in this Sudoku is the product of the two numbers in adjacent cells.
Make your own double-sided magic square. But can you complete both sides once you've made the pieces?
Countries from across the world competed in a sports tournament. Can you devise an efficient strategy to work out the order in which they finished?
The letters in the following addition sum represent the digits 1 ... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
The letters of the word ABACUS have been arranged in the shape of a triangle. How many different ways can you find to read the word ABACUS from this triangular pattern?
A few extra challenges set by some young NRICH members.
Rather than using the numbers 1-9, this sudoku uses the nine different letters used to make the words "Advent Calendar".
A game for 2 people. Take turns placing a counter on the star. You win when you have completed a line of 3 in your colour.
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.
You need to find the values of the stars before you can apply normal Sudoku rules.
Find the smallest whole number which, when mutiplied by 7, gives a product consisting entirely of ones.
There is a long tradition of creating mazes throughout history and across the world. This article gives details of mazes you can visit and those that you can tackle on paper.
This tricky challenge asks you to find ways of going across rectangles, going through exactly ten squares.
A challenging activity focusing on finding all possible ways of stacking rods.
Place the 16 different combinations of cup/saucer in this 4 by 4 arrangement so that no row or column contains more than one cup or saucer of the same colour.
You have been given nine weights, one of which is slightly heavier than the rest. Can you work out which weight is heavier in just two weighings of the balance?
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.
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.
Bellringers have a special way to write down the patterns they ring. Learn about these patterns and draw some of your own.
A man has 5 coins in his pocket. Given the clues, can you work out what the coins are?
This challenge extends the Plants investigation so now four or more children are involved.
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
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.
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?
Mr McGregor has a magic potting shed. Overnight, the number of plants in it doubles. He'd like to put the same number of plants in each of three gardens, planting one garden each day. Can he do it?
Given the products of adjacent cells, can you complete this Sudoku?
A dog is looking for a good place to bury his bone. Can you work out where he started and ended in each case? What possible routes could he have taken?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
Whenever a monkey has peaches, he always keeps a fraction of them each day, gives the rest away, and then eats one. How long could he make his peaches last for?
A student in a maths class was trying to get some information from her teacher. She was given some clues and then the teacher ended by saying, "Well, how old are they?"
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?
Your challenge is to find the longest way through the network following this rule. You can start and finish anywhere, and with any shape, as long as you follow the correct order.
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?
Can you find which shapes you need to put into the grid to make the totals at the end of each row and the bottom of each column?
Can you use the information to find out which cards I have used?
Four friends must cross a bridge. How can they all cross it in just 17 minutes?
Different combinations of the weights available allow you to make different totals. Which totals can you make?
There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?
What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Alice and Brian are snails who live on a wall and can only travel along the cracks. Alice wants to go to see Brian. How far is the shortest route along the cracks? Is there more than one way to go?
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Find the sum and difference between a pair of two-digit numbers. Now find the sum and difference between the sum and difference! What happens?
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.