Or even "once you're dressed, I can tell you something about Mercury". I agree that it shouldn't be a reward - more a thing to do or discuss after the task is

Or even "once you're dressed, I can tell you something about Mercury". I agree that it shouldn't be a reward - more a thing to do or discuss after the task is done that isn't an option before it's done. Because as I imagine most parents know, any perceived offered reward does become grounds for negotiation.