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.
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
The number of plants in Mr McGregor's magic potting shed increases
overnight. He'd like to put the same number of plants in each of
his gardens, planting one garden each day. How can he do it?
Triangle numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?
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?
We can show that (x + 1)² = x² + 2x + 1 by considering
the area of an (x + 1) by (x + 1) square. Show in a similar way
that (x + 2)² = x² + 4x + 4
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.
A game for 2 players that can be played online. Players take it in turns to select a word from the 9 words given. The aim is to select all the occurrences of the same letter.
Slide the pieces to move Khun Phaen past all the guards into the position on the right from which he can escape to freedom.
A game for 2 players. Can be played online. One player has 1 red
counter, the other has 4 blue. The red counter needs to reach the
other side, and the blue needs to trap the red.
A game for 1 person to play on screen. Practise your number bonds
whilst improving your memory
Can you spot the similarities between this game and other games you
know? The aim is to choose 3 numbers that total 15.
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?
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?
Euler discussed whether or not it was possible to stroll around Koenigsberg crossing each of its seven bridges exactly once. Experiment with different numbers of islands and bridges.
Interactive game. Set your own level of challenge, practise your table skills and beat your previous best score.
Practise your diamond mining skills and your x,y coordination in this homage to Pacman.
A game for 2 people that everybody knows. You can play with a
friend or online. If you play correctly you never lose!
Here is a chance to play a version of the classic Countdown Game.
Semi-regular tessellations combine two or more different regular polygons to fill the plane. Can you find all the semi-regular tessellations?
What are the coordinates of the coloured dots that mark out the
tangram? Try changing the position of the origin. What happens to
the coordinates now?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
An interactive game to be played on your own or with friends.
Imagine you are having a party. Each person takes it in turns to
stand behind the chair where they will get the most chocolate.
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
These formulae are often quoted, but rarely proved. In this article, we derive the formulae for the volumes of a square-based pyramid and a cone, using relatively simple mathematical concepts.
You have 27 small cubes, 3 each of nine colours. Use the small cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of every colour.
Use the interactivity to play two of the bells in a pattern. How do
you know when it is your turn to ring, and how do you know which
bell to ring?
It's easy to work out the areas of most squares that we meet, but
what if they were tilted?
Can you complete this jigsaw of the multiplication square?
A and B are two interlocking cogwheels having p teeth and q teeth respectively. One tooth on B is painted red. Find the values of p and q for which the red tooth on B contacts every gap on the. . . .
Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!
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?
A tilted square is a square with no horizontal sides. Can you
devise a general instruction for the construction of a square when
you are given just one of its sides?
A game for 2 people that can be played on line or with pens and paper. Combine your knowledege of coordinates with your skills of strategic thinking.
A generic circular pegboard resource.
An interactive activity for one to experiment with a tricky tessellation
Use the interactivity to listen to the bells ringing a pattern. Now
it's your turn! Play one of the bells yourself. How do you know
when it is your turn to ring?
A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.
An interactive game for 1 person. You are given a rectangle with 50 squares on it. Roll the dice to get a percentage between 2 and 100. How many squares is this? Keep going until you get 100. . . .
The aim of the game is to slide the green square from the top right
hand corner to the bottom left hand corner in the least number of
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
Exchange the positions of the two sets of counters in the least possible number of moves
A card pairing game involving knowledge of simple ratio.
An environment which simulates working with Cuisenaire rods.
NRICH December 2006 advent calendar - a new tangram for each day in
the run-up to Christmas.
Watch this film carefully. Can you find a general rule for
explaining when the dot will be this same distance from the
Work out the fractions to match the cards with the same amount of
Can you find a relationship between the number of dots on the
circle and the number of steps that will ensure that all points are