### Arithmagons Poster

Arithmagons Poster

### Squares in Rectangles Poster

Squares In Rectangles Poster

### Isosceles Triangles Poster

Isosceles Triangles Poster - February 2005

# Multiplication Square Poster

##### Age 11 to 14Challenge Level

For 2 by 2 squares, the difference between the diagonal sums is always 1

For 3 by 3 squares, the difference between the diagonal sums is always 4

For 4 by 4 squares, the difference between the diagonal sums is always 10

Why?

Say the top left corner of the square is on $a\times b$.

2 by 2 square:

3 by 3 square:

4 by 4 square: