10 - 9 %2b 8 - 7 %2b 6 - 5 %2b 4 - 3 %2b 2 - 1

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.