How to always win at Christmas crackers
Have you ever wondered how to win at Christmas crackers?
Well a combination of science and maths means that you can win every time you pull one during the festive season.
It's worth mentioning though that you're on your own when it comes to stopping your hat, joke or key-ring falling in your gravy!
For the last 200 years the Royal Institution in London has held Christmas Lectures which explain how science is involved in everything we do. This year the focus is on maths.
Dr Hannah Fry is presenting the lectures and she met up with Royal Institute scientist and CBBC presenter Fran Scott to explain what it's all about.
The Christmas Lectures will be on BBC4 on 26, 27 and 28 December.