I'll Read Your Birthday

Give me one number built from the month and day you were born, and I'll give you the date back.

You'll do the work on this one, and it's all arithmetic you can manage in your head or on the calculator you're already holding. Take the month you were born, run it through the steps as they appear, then add the day.

One number comes out the other end. Tell me that number and nothing else. Not the month, not the day, not your age.

How it works

The steps multiply your birth month by a fixed amount and add a constant before the day is added on. That pushes the month into the hundreds and leaves the day sitting in the last two digits, where it can't interfere. Subtract the constant at the end and the number splits cleanly: month on one side, day on the other. It's reversible arithmetic, not a lucky guess, which is why it never misses.

Props
A calculator, if you'd rather not do it in your head
Difficulty
Easy to learn, worth practising

Dates go fast

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Close-up magic, mentalism and stage shows for corporate events, parties, churches and theatres.

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Based in Milwaukee · performing across Wisconsin · travelling nationwide