You may also like

problem icon


This activity investigates how you might make squares and pentominoes from Polydron.

problem icon

Eight Dominoes

Using the 8 dominoes make a square where each of the columns and rows adds up to 8

problem icon

Prime Magic

Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?

Coordinate Challenge

Stage: 2 Challenge Level: Challenge Level:1

We had lots of solutions to this problem but not many of you told us how you got your solutions. Luis and Freddie, who go to Newton Prep, sent in well-explained solutions. Here is what Luis wrote:

The first thing I worked out is that the letter at (4,2) is not symmetrical in any way, the only letter that isn't symmetrical in any way is the letter P.
Then I worked out that at (0,2) and (1,2) are the ends of the alphabet and had to be A and Z but I needed to know which one went where so I looked at the clues. One said that (0,2) and (2,0) have rotational symmetry which means that A is on (1,2) and Z is on (0,2).
Then I saw the clue that said that (3,3), (3,2) and (3,1) are all consecutive in the alphabet, because the A and the Z are already used, it has to be C, D and E because it says that (3,3) is made of only curved lines.
Then I saw that one of the clues said that (2,0) is only made of curved lines, so (2,0) is the S.
(4,2) is not symmetrical in any way so (4,2) is a P.
The first clue says that (1,1) and (1,3) have a vertical line of symmetry, another clue says that (1,1) also has a vertical line of symmetry, which means that (1,1) is a X and (1,3) is a Y, which leaves the B which is at (2,1) because a clue says that at (2,1) there is a letter with a horizontal line of symmetry.

Many children from Stradbroke Primary School sent an image of their solution. Here is George's:


Well done!