Get a pencil and paper. Got it _{Type OK to continue...}?

Think of any 4 digit number. Like... 4823. Pick some different numbers (variety is the spice of Sporcle) Write it down. _{Type OK to continue...}?

Great! Now jumble those numbers around and write down that number. For example, if I had 4823 I might choose 2834 or 8432. Got it? _{Type OK to continue...}?

Here's the hard part. Subtract the smaller number from the larger number. For example 4823-2834=1989. _{Type OK to continue...}?

You have a new number now. Circle one of the digits in that number. Any digit will do (but don't circle a zero... that's already a circle!) _{Type OK to continue...}?

Type in the other numbers now (in any order) followed by 'ok'. Did Sporcle read you mind (again)?

Try it again. If it didn't get it, check your math.

You circled 1

You circled 2

You circled 3

You circled 4

You circled 5

You circled 6

You circled 7

You circled 8

You circled 9

You circled 1

You circled 2

You circled 3

You circled 4

You circled 5

You circled 6

You circled 7

You circled 8

You circled 9

What?!? Check your math. I am NEVER wrong! _{Or did you end up with a 1 digit number? Tsk.}