13. Zero is not represented in Roman numerals.

14. The word “mathematics” only appears in one Shakespearean play, “The Taming of the Shrew”.

15. -40 °C is equal to -40 °F.

16. In France, a pie chart is sometimes referred to as a “camembert”.

17. The symbol for division (i.e.÷) is called an obelus.l

18. 2 and 5 are the only prime numbers that end in 2 or 5.

19. A ‘jiffy’ is an actual unit of time. It means 1/100th of a second

20. If you shuffle a deck of cards properly, it’s more than likely that the exact order of the cards you get has never been seen before in the whole history of the universe.