Being resilient

Using your knowledge of the properties of numbers, can you fill all the squares on the board?

Find the frequency distribution for ordinary English, and use it to help you crack the code.

The clues for this Sudoku are the product of the numbers in adjacent squares.

A 2 by 3 rectangle contains 8 squares and a 3 by 4 rectangle contains 20 squares. What size rectangle(s) contain(s) exactly 100 squares? Can you find them all?

Are these games fair? How can you tell?

How many different triangles can you make on a circular pegboard that has nine pegs?

Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?

Use these head, body and leg pieces to make Robot Monsters which are different heights.

Can you find a cuboid that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?

Four bags contain a large number of 1s, 3s, 5s and 7s. Can you pick any ten numbers from the bags so that their total is 37?