Everyone has tried to guess someone’s age before, but, if you’re a magician and you’re in a show, getting it incorrect can mean creating bad vibes between you and your audience.

If, however, you memorize this math-based trick, you will actually be able to tell anyone their age.

**All you need for this trick is a calculator.**

To help people see your calculator, try to get one with big buttons and a big screen.

That’s really for their benefit, not yours!

You might even decide to show the calculator through a projector screen if you’re performing this in front of a large crowd.

## How it works

### First, have your participant to pick a number between 1 and 10.

You will also decipher this number by the end of the trick.

Ask them to multiply it by 2.

Pause to tell them that you’re sorry, and you didn’t realize the math might be too hard for them, so you’ll get them a calculator.

### Second, Walk them through selecting their number and multiplying it by 2 again on the calculator.

This is a great opportunity to build some humour into the act. Continue this humour by asking them to get ready for some big math before telling them to add 5 to their current value.

### Then, actually move into the big math.

Ask them to multiply the current number by 50.

Then, ask them if they’ve had their birthday yet this year.

**If they say no,** ask them to add the first number from the pair of numbers on the list below.

**If they say yes,** ask them to add the second number.

**This number changes yearly, so here is a chart to reference:**

2016: +1765 or +1766

2017: +1766 or +1767

2018: +1767 or +1768

2019: +1768 or +1769

2020: +1769 or +1770

2021: +1770 or +1771

2022: +1771 or +1772

After they add this number in, tell them NOT to say it out loud, but to subtract their birth year.

Then, say “That’s it!”

They’ll be confused because they will have a three-digit number far too large to be their age. You can act confused as well, and take the calculator from them.

The first digit of the three-digit number is the number they picked.

### The remaining number is their age.

Put on a show sharing this information with the audience, and you’ve successfully guessed both their age and the number they chose at the start of the trick without hurting any feelings.

At the end of it, people will think you are a mind reader.

And all it took was some simple math!

## Watch it in action!

Watch the same magic trick you learned above, and see how it works on you!