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. How many different journeys could you make if you were going to visit four stations in this network? How about if there were five stations? Can you predict the number of journeys for seven stations? 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? Given the nets of 4 cubes with the faces coloured in 4 colours, build a tower so that on each vertical wall no colour is repeated, that is all 4 colours appear. A little mouse called Delia lives in a hole in the bottom of a tree..... How many days will it be before Delia has to take the same route again? 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? My dice has inky marks on each face. Can you find the route it has taken? What does each face look like? 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. Find all the different shapes that can be made by joining five equilateral triangles edge to edge. How can you put five cereal packets together to make different shapes if you must put them face-to-face? On my calculator I divided one whole number by another whole number and got the answer 3.125. If the numbers are both under 50, what are they? Problem solving is at the heart of the NRICH site. All the problems give learners opportunities to learn, develop or use mathematical concepts and skills. Read here for more information. This Sudoku, based on differences. Using the one clue number can you find the solution?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? Four small numbers give the clue to the contents of the four surrounding cells. 60 pieces and a challenge. What can you make and how many of the pieces can you use creating skeleton polyhedra? Arrange eight of the numbers between 1 and 9 in the Polo Square below so that each side adds to the same total. There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs. Can you use your powers of logic and deduction to work out the missing information in these sporty situations? Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families? 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? This task, written for the National Young Mathematicians' Award 2016, involves open-topped boxes made with interlocking cubes. Explore the number of units of paint that are needed to cover the boxes. . . . Alice's mum needs to go to each child's house just once and then back home again. How many different routes are there? Use the information to find out how long each road is on the route she took. Pentagram Pylons - can you elegantly recreate them? Or, the European flag in LOGO - what poses the greater problem? Explore this how this program produces the sequences it does. What are you controlling when you change the values of the variables? 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. Suppose we allow ourselves to use three numbers less than 10 and multiply them together. How many different products can you find? How do you know you've got them all? This task, written for the National Young Mathematicians' Award 2016, invites you to explore the different combinations of scores that you might get on these dart boards. 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? This task, written for the National Young Mathematicians' Award 2016, focuses on 'open squares'. What would the next five open squares look like? There are lots of different methods to find out what the shapes are worth - how many can you find? Exactly 195 digits have been used to number the pages in a book. How many pages does the book have? Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores. What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters. Tim had nine cards each with a different number from 1 to 9 on it. How could he have put them into three piles so that the total in each pile was 15? In this article, the NRICH team describe the process of selecting solutions for publication on the site. How could you put eight beanbags in the hoops so that there are four in the blue hoop, five in the red and six in the yellow? Can you find all the ways of doing this? Can you use the information to find out which cards I have used? In the planet system of Octa the planets are arranged in the shape of an octahedron. How many different routes could be taken to get from Planet A to Planet Zargon? This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up? Look carefully at the numbers. What do you notice? Can you make another square using the numbers 1 to 16, that displays the same properties? Advent Calendar 2011 - a mathematical activity for each day during the run-up to Christmas. In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication? Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible? This magic square has operations written in it, to make it into a maze. Start wherever you like, go through every cell and go out a total of 15! In this Sudoku, there are three coloured "islands" in the 9x9 grid. Within each "island" EVERY group of nine cells that form a 3x3 square must contain the numbers 1 through 9. These eleven shapes each stand for a different number. Can you use the number sentences to work out what they are? Place six toy ladybirds into the box so that there are two ladybirds in every column and every row. Can you put plus signs in so this is true? 1 2 3 4 5 6 7 8 9 = 99 How many ways can you do it?