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.