trade vs exchange

[curiousmarcus]

Child A wants Child B's crayon while Child B wants Child A's crayon.

Either of them would say:

1. Let's trade.
2. Let's exchange.

Which is more natural?

 

[Rover_KE]

3. Let's swap.

That's what British children say.

 

[GoesStation]

American children say let's trade.