### Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

### Calendar Capers

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

### Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

# Magic Octahedron

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

The diagram show the net of a regular octahedron.

In a magic octahedron, the four numbers on the faces that meet at a vertex add up to make the same total for every vertex. If the letters $F, G, H, J$ and $K$ are replaced with the numbers $2$, $4$, $6$, $8$, and some other number, in some order, to make a magic octahedron, what is the value of $G + J$?

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

This problem is taken from the UKMT Mathematical Challenges.