Step 1: Show the audience a bank note.

Step 2: Fold it in half as shown.

Step 3: And then again in half.

Step 4: And again.

Step 5: You should have this.

Step 6: And now unfold the bank note in reverse. Nothing about it has changed.

Step 7: Repeat, folding up the bank note as before. And unfold it. Now the bank note is upside-down, although everyone saw that you didn’t turn it over.

Step 8: The secret is that the second time around, you unfolded the bank note in a slightly different way.

Step 9: Unfold it backward, not forward.

Step 10: And at the end, unfold it upward as before.

Step 11: There is, in fact, another way to unfold the bank note. It’s worth memorizing. At first, unfold it like the first time.

Step 12: And only at the second step unfold it backward.

Step 13: And then, as usual, unfold upward. Unfold the bank note quickly, and no one will notice that you did something different at the second step.