Working systematically

problem
LOGO challenge - the logic of LOGO

Age

11 to 16

Challenge level

Just four procedures were used to produce a design. How was it done? Can you be systematic and elegant so that someone can follow your logic?
problem
Bell ringing

Age

11 to 14

Challenge level

Suppose you are a bellringer. Can you find the changes so that, starting and ending with a round, all the 24 possible permutations are rung once each and only once?
problem
Intersection Sudoku 1

Age

11 to 16

Challenge level

A Sudoku with a twist.
problem
Ratio Sudoku 1

Age

11 to 16

Challenge level

A Sudoku with clues as ratios.
problem
So many sums

Age

11 to 14

Challenge level

In this addition each letter stands for a different digit, with S standing for 3. What is the value of YxO?
problem
Constellation Sudoku

Age

14 to 18

Challenge level

Special clue numbers related to the difference between numbers in two adjacent cells and values of the stars in the "constellation" make this a doubly interesting problem.
problem
Blockupied

Age

11 to 14

Challenge level

A 1x2x3 block is placed on an 8x8 board and rolled several times.... How many squares has it occupied altogether?
problem
Pole star Sudoku 2

Age

11 to 16

Challenge level

This Sudoku, based on differences. Using the one clue number can you find the solution?
problem
Even squares

Age

11 to 14

Challenge level

Can you find squares within a number grid whose entries add up to an even total?
problem
Quadruple Sudoku

Age

11 to 16

Challenge level

Four small numbers give the clue to the contents of the four surrounding cells.