Working systematically

Can you find out in which order the children are standing in this line?

A Sudoku based on clues that give the differences between adjacent cells.

This train line has two tracks which cross at different points. Can you find all the routes that end at Cheston?

Try to solve this very difficult problem and then study our two suggested solutions. How would you use your knowledge to try to solve variants on the original problem?

This is a variation of sudoku which contains a set of special clue-numbers. Each set of 4 small digits stands for the numbers in the four cells of the grid adjacent to this set.

The squares of this grid contain one of the letters P, Q, R and S. Can you complete this square so that touching squares do not contain the same letter? How many possibilities are there?

Six new homes are being built! They can be detached, semi-detached or terraced houses. How many different combinations of these can you find?

Investigate the different ways you could split up these rooms so that you have double the number.

Can you arrange 5 different digits (from 0 - 9) in the cross in the way described?

Make a pair of cubes that can be moved to show all the days of the month from the 1st to the 31st.