Test Your MagicTHE PRACTICE BEFORE THE APPLAUSE

ACT II / THE NUMBER LAB

A different beginning.
The same curious ending.

Choose a three-digit number whose first and last digits differ by at least two. The lab shows every step: reverse, subtract, reverse and add.

Use 100–999. The first and last digits must differ by at least two. Letters, decimals and leading-zero inputs do not count.

THE LITTLE PREDICTION

1089

The result is shown openly because this is a practice lab. Enter a valid number to see how it gets there.

    Why the condition matters

    Reversing a three-digit number changes the hundreds and units positions. Their difference therefore gives a multiple of 99. Under our starting condition, the positive difference is one of 198, 297, 396, 495, 594, 693, 792 or 891. Each one plus its reverse is 1089.

    The first and last digit condition keeps this version simple. An invalid starting number gets an explanation rather than a fabricated success. The middle digit can vary without changing the subtraction result.

    For a performance, write a paper prediction before starting and use clear audience instructions. Read the presentation notes →