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?
Let's suppose that you are going to have a magazine which has 16
pages of A5 size. Can you find some different ways to make these
pages? Investigate the pattern for each if you number the pages.
I was in my car when I noticed a line of four cars on the lane next
to me with number plates starting and ending with J, K, L and M.
What order were they in?
A particular technique for solving Sudoku puzzles, known as "naked pair", is explained in this easy-to-read article.
How many ways can you find to do up all four buttons on my coat? How about if I had five buttons? Six ...?
Given the products of diagonally opposite cells - can you complete this Sudoku?
Follow the clues to find the mystery number.
Make a pair of cubes that can be moved to show all the days of the
month from the 1st to the 31st.
Use the clues to work out which cities Mohamed, Sheng, Tanya and
Bharat live in.
You are given the Lowest Common Multiples of sets of digits. Find
the digits and then solve the Sudoku.
This Sudoku, based on differences. Using the one clue number can you find the solution?
Only one side of a two-slice toaster is working. What is the
quickest way to toast both sides of three slices of bread?
Four small numbers give the clue to the contents of the four
This challenge, written for the Young Mathematicians' Award, invites you to explore 'centred squares'.
Seven friends went to a fun fair with lots of scary rides. They
decided to pair up for rides until each friend had ridden once with
each of the others. What was the total number rides?
A Latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and exactly once in each column.
Look carefully at the numbers. What do you notice? Can you make
another square using the numbers 1 to 16, that displays the same
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.
If these elves wear a different outfit every day for as many days
as possible, how many days can their fun last?
Bellringers have a special way to write down the patterns they
ring. Learn about these patterns and draw some of your own.
Can you use your powers of logic and deduction to work out the missing information in these sporty situations?
This challenge is to design different step arrangements, which must
go along a distance of 6 on the steps and must end up at 6 high.
Stuart's watch loses two minutes every hour. Adam's watch gains one
minute every hour. Use the information to work out what time (the
real time) they arrived at the airport.
Can you help the children find the two triangles which have the
lengths of two sides numerically equal to their areas?
George and Jim want to buy a chocolate bar. George needs 2p more
and Jim need 50p more to buy it. How much is the chocolate bar?
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?
You need to find the values of the stars before you can apply normal Sudoku rules.
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?
A merchant brings four bars of gold to a jeweller. How can the
jeweller use the scales just twice to identify the lighter, fake
Use the clues to find out who's who in the family, to fill in the family tree and to find out which of the family members are mathematicians and which are not.
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.
Nina must cook some pasta for 15 minutes but she only has a 7-minute sand-timer and an 11-minute sand-timer. How can she use these timers to measure exactly 15 minutes?
Explore this how this program produces the sequences it does. What
are you controlling when you change the values of the variables?
60 pieces and a challenge. What can you make and how many of the
pieces can you use creating skeleton polyhedra?
Just four procedures were used to produce a design. How was it
done? Can you be systematic and elegant so that someone can follow
Place the numbers 1 to 8 in the circles so that no consecutive
numbers are joined by a line.
Place eight queens on an chessboard (an 8 by 8 grid) so that none
can capture any of the others.
A Sudoku with a twist.
Arrange eight of the numbers between 1 and 9 in the Polo Square
below so that each side adds to the same total.
Investigate the different ways you could split up these rooms so
that you have double the number.
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 cannot choose a selection of ice cream flavours that includes totally what someone has already chosen. Have a go and find all the different ways in which seven children can have ice cream.
This pair of linked Sudokus matches letters with numbers and hides a seasonal greeting. Can you find it?
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?
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?
Systematically explore the range of symmetric designs that can be
created by shading parts of the motif below. Use normal square
lattice paper to record your results.
What is the date in February 2002 where the 8 digits are
palindromic if the date is written in the British way?
A Sudoku that uses transformations as supporting clues.
A Sudoku with clues as ratios.
These are the faces of Will, Lil, Bill, Phil and Jill. Use the clues to work out which name goes with each face.