A Number Quiz for those who like them (but please ignore if you don't)!

It seems people on LinkedIn love doing number quizzes but, to be honest, most of those I've seen claim you need to be a genius to solve them when they are actually quite easy.

So I thought I'd post a harder one to while away a minute or two (or ten).

There are plenty of clues for this puzzle (if you look in the right places). It's a puzzle that tends to appear periodically but only needs elementary arithmetic to solve it.

Feel free to post your answer. I guarantee if you do solve it, you will know without a shadow of a doubt that you are right, but please don't spoil it for other by posting the rationale in the comments.