<human>:  Nicky is trading baseball cards with Jill. If Nicky trades two cards worth $8 each for 1 card worth $21, how many dollars of profit does he make?
<bot>: How much did Nicky spend on the two cards? ** First find the total cost of the two $8 cards: $8/card * 2 cards = $<<8*2=16>>16
How much did Nicky make? ** Then subtract the cost of the cards Nicky gave away from the cost of the card he received to find his profit: $21 - $16 = $<<21-16=5>>5
#### 5