Working systematically

problem

Intersection Sudoku 2

Age

11 to 16

Challenge level

A Sudoku with a twist.
problem

Alphabetti Sudoku

Age

11 to 16

Challenge level

This Sudoku requires you to do some working backwards before working forwards.
problem

Mini Kakuro

Age

11 to 14

Challenge level

The sum of each column and row in this grid give the totals as shown. What number goes in the starred square?
problem

Dicey directions

Age

14 to 16

Challenge level

An ordinary die is placed on a horizontal table with the '1' face facing East... In which direction is the '1' face facing after this sequence of moves?
problem

Simple train journeys

Age

5 to 11

Challenge level

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?
problem

9 weights

Age

11 to 14

Challenge level

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?
problem

Twin chute-swapping Sudoku

Age

14 to 18

Challenge level

A pair of Sudokus with lots in common. In fact they are the same problem but rearranged. Can you find how they relate to solve them both?
problem

Advent Sudoku

Age

11 to 14

Challenge level

Rather than using the numbers 1-9, this sudoku uses the nine different letters used to make the words "Advent Calendar".
problem

A first product Sudoku

Age

7 to 14

Challenge level

Given the products of adjacent cells, can you complete this Sudoku?
problem

Simultaneous equations Sudoku

Age

11 to 18

Challenge level

Solve the equations to identify the clue numbers in this Sudoku problem.