Calendar Capers

Choose any three by three square of dates on a calendar page...

Latin Numbers

Can you create a Latin Square from multiples of a six digit number?

Counting Factors

Is there an efficient way to work out how many factors a large number has?

Magic 7

Stage: 3 Short Challenge Level:
See all short problems arranged by curriculum topic in the short problems collection

In this magic square, which uses all whole numbers from $7$ to $15$ inclusive, each of the rows, columns and the two main diagonals has the same total.

Which number replaces $n$ in the completed square?

If you liked this problem, here is an NRICH task that challenges you to use similar mathematical ideas.

This problem is taken from the UKMT Mathematical Challenges.