This trick to guess someone’s age and shoe size is pure witchcraft

A magic trick that can "guess" your age and shoe-size has been confusing people on the internet this week.

The trick involves asking someone to write down their shoe size without telling you. They must then multiply the figure by 5, add 50, multiply that number by 20, add 1015, and subtract the year of their birth. They should be left with a figure that includes their shoe size and age, making up a three or four digit number. Although it's been around for a while, it is probably doing the rounds now because January is the best time to do the trick. This is down to the fact that once your birthday has passed, the numbers are out, so the earlier in the year the better.