# Did you solve it? How to turn your kid into a maths wiz | Mathematics

Earlier today I set you six puzzles that use a square piece of paper, in the light of new research saying that the best way to improve maths performance is to train ‘spatial reasoning’ using physical objects.

1. The triangle fold

Fold a square paper in such a way that fold lines (and possibly an edge) mark an equilateral triangle. (Compass and ruler not allowed!)

Solution Here is one way, that uses the side length of the square as the side length of the triangle.

It is possible to fold a larger equilateral triangle – I’ll leave that as an exercise for the reader. Clue: the tip of the triangle is still a corner of the square, but the sides are folded at 15 degrees from the sides of the square.

2. The 3D shape

Can you fold a square sheet of paper so that it makes a closed 3D shape, with no overlaps, gaps or extraneous flaps of paper? You cannot, for example, fold the square to make a cube since you will create an overlap or extra flaps.

Solution Yes you can, and here is one: a pyramid with an isosceles triangle as a base.

Hole punch puzzles

For each of the next puzzles, you must take a square piece of paper and fold it, using as many folds as is needed, so that if you punch a single hole through the folded paper you will match the image when the paper is fully unfolded .

3 The X.

Solution

4. The diagonal.

Solution

5. The ring.

Solution

6. A hole punch in the head.

Solution The first fold divides the right 3/4 of the square into half.