Have a think about how we use the letter X.  If you’re marking something, it’s ticks for correct and crosses – or Xs – for incorrect.

Putting an X in the box is how we vote.

X is used to denote an unknown quantity, which you’ll remember from trying to solve equations at school or if you’ve ever watched an old-fashioned detective drama when the villain is known as Mr or Miss X.

What about treasure maps, where X marks the spot?

Or a spot the ball competition, where you had a picture from a football match but with the football removed and you had to guess where the centre of the ball would be and mark it with an X.

Or, of course you’ve got things like xylophone, xenon (a gas), or everybody’s favourite – X-Ray.

However, if you don’t fancy writing about any of those – and we understand that X is a difficult letter – then write whatever you want to. Go on, have a free week!

Let’s hear your stories, poems or pieces of writing connected to X – or not!

Send them to louise.hulland@bbc.co.uk