Guess a Birthday

1. Think of two numbers
      (1) the number of the month in which you were born and
      (2) the number of the day of the month on which you were born.

2. Multiply the month number by 5.

3. Add 6.

4. Multiply by 4.

5. Add 9.

6. Multiply by 5.

7. Add the Day on which you were born.

Enter the total here:


Many thanks to Jaime Garcia Ramirez for helping me with the javascript!


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Click here to see why it works