Click flag and then arrow keys (left = back; right = next) or press space to go to next slide. Step 1: Get a piece of paper. Step 2: Write down a 5-digit number on it. Step 3: Fold it up and put it in visible sight. Step 4: Get a new piece of paper and write down the last 4-digit number of that 5-digit number + 2. Step 5: Ask the person for a 4-digit number. Step 6: You give a 4-digit number (when you add the two numbers up you get 9999) Step 7: Repeat steps 5 and 6. Step 8: Now when you add all 5 numbers up you get that 5-digit number. :)