Behind My Back by Abhinav Bothra

The spectator selects 4 cards while the performer is facing away.
After selection, the performer turns his back toward the spectator.
The spectator shuffles the 4 cards and holds 2 in each hand.

With performer's back turned towards the spectator
He is able to call out the sum of the values of the card in each hand.
He proceeds to identify the cards.
And even calls out which card is in which hand.

- Uses NO MARKED CARDS.
- No Gimmicks
- Can be done with a BORROWED DECK with a setup lasting less than 20 seconds. (No, you do not bend the cards or inflict any damage whatsoever)