Working systematically

problem
Zargon glasses

Age

7 to 11

Challenge level

Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families?
problem
Arranging the tables

Age

7 to 11

Challenge level

There are 44 people coming to a dinner party. There are 15 square tables that seat 4 people. Find a way to seat the 44 people using all 15 tables, with no empty places.
problem
Team scream

Age

7 to 11

Challenge level

Seven friends went to a fun fair with lots of scary rides. They decided to pair up for rides until each friend had ridden once with each of the others. What was the total number rides?
problem
Egyptian rope

Age

7 to 11

Challenge level

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?
problem
Map folding

Age

7 to 11

Challenge level

Take a rectangle of paper and fold it in half, and half again, to make four smaller rectangles. How many different ways can you fold it up?
problem
Wonky watches

Age

7 to 11

Challenge level

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?
problem
Forgot the numbers

Age

7 to 11

Challenge level

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?
problem
Creating cubes

Age

7 to 11

Challenge level

Arrange 9 red cubes, 9 blue cubes and 9 yellow cubes into a large 3 by 3 cube. No row or column of cubes must contain two cubes of the same colour.
problem
Amy's dominoes

Age

7 to 11

Challenge level

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

Age

7 to 11

Challenge level

Can you draw a square in which the perimeter is numerically equal to the area?