Working systematically

Can you find the missing number(s)? The square is the average (mean) of the numbers surrounding it.

Can you find combinations of strips of paper which equal the length of the black strip? If the length of the black is 1, how could you write the sum of the strips?

Can you find pairs of differently sized windows that cost the same?

Roll two red dice and a green dice. Add the two numbers on the red dice and take away the number on the green. What are all the different possible answers?

What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.

Can you go through this maze so that the numbers you pass add to exactly 100?

The ancient Egyptians were said to make right-angled triangles using a rope with twelve equal sections divided by knots. What other triangles could you make if you had a rope like this?

Mandeep's watch loses two minutes every hour. Adam's watch gains one minute every hour. Can you work out what time they arrived at the airport?

On my calculator I divided one whole number by another whole number and got the answer 3.125. If the numbers are both under 50, what are they?

Amy has a box containing domino pieces but she does not think it is a complete set. Which of her domino pieces are missing?