**The number nine: (ages 7 – 12)**

*Ask your audience to do the following steps:*

- Pick a 2-digit number from 1 to 50… say 25
- Add the two digits together.
- Subtract that sum of digits from the original number.
- If their answer is a 2-digit number, ask them to add the digits.

*Reveal to them that you can read their mind. No matter what number they pick, the answer is always*

**9**.

**Grey elephants in Denmark: (ages 9 to adult)**

*Each person in the audience is asked to think of a small number(between 1 and 30 is usually preferred) and is then instructed to perform the following operations*silently

*.*

- Double the number.
- Add 8 to the result.
- Divide the result by 2.
- Subtract the original number…
- Convert this into a letter of the alphabet. (1=A, 2=B, 3=C, 4=D, etc.)
- Think of the name of a country which starts with this letter.
- Think of an animal whose name starts with the country’s
*second* - Think of the
*color*of that animal…

*You then ponder(whilst scratching your head) and state to the puzzled audience that their collective thinking must have gone wrong, since “*

**there are no grey elephants in Denmark**“…**Magic 27: (ages 9 to adult)**

*Tell your audience or your classroom that you can read their minds. No sleight of hand. Just pure math magic.*

- Deal any odd number of cards up to 27 in three equal piles (this means you’re dealing 15, 21 or 27 cards, according to taste).
- Ask what pile the chosen card belongs to and collate the cards so the chosen pile is in the middle.
- Deal and collate again in the same way.
- Deal one last time.

*The chosen card will be in the middle of the selected row. Reveal it in whatever dramatic way you like…*For a very fast effect, use just 9 cards and deal only twice (although the underlying math for this 2-step trick becomes rather obvious).

**1089 (ages 7 to adult)**

*Try this with a*

**math expert**. Probably one that you go to for math homework help with your school’s math worksheets. Ask the tutor to pick a 3-digit number where the first and last digits differ by 2 or more…- Consider the “reverse” number, obtained by reading it backwards.
- Subtract the smaller of these two numbers from the larger one.
- Add the result to its own reverse.

*Reveal to the*Most times, students, and even math tutors view math as a rather dull subject. These tricks will not only dispel that notion, but may elevate a lowly geek to star status at parties!

**math expert**that the answer is 1089. Watch the reaction!