Reasoning, convincing and proving

problem
4 by 4 Mathdokus

Age

7 to 14

Challenge level

Can you use the clues to complete these 4 by 4 Mathematical Sudokus?
problem
3 by 3 Mathdokus

Age

7 to 14

Challenge level

Can you use the clues to complete these 3 by 3 Mathematical Sudokus?
problem
Is there more to discover about four consecutive numbers?

Age

14 to 16

Challenge level
problem
Continuing to explore four consecutive numbers

Age

14 to 16

Challenge level
problem
Starting to explore four consecutive numbers

Age

11 to 16

Challenge level
problem
Isosceles seven

Age

14 to 16

Challenge level

Is it possible to find the angles in this rather special isosceles triangle?
problem
Counting stick conjectures

Age

5 to 11

Challenge level

How many rectangles can you see? Are they all the same size? Can you predict how many rectangles there will be in counting sticks of different lengths?
problem
Triangle in a square

Age

7 to 11

Challenge level

Do you agree with Badger's statements? Is Badger's reasoning watertight? Why or why not?
problem
Diagonally square

Age

7 to 11

Challenge level

Ayah conjectures that the diagonals of a square meet at right angles. Do you agree? How could you find out?
problem
Proof sorter - circumference angles

Age

11 to 16

Challenge level