Every dad's favorite car game

I don't know about you, but when Dad got tired of us arguing in the back seat he always pulled out a classic car game.

D: I'm thinking of a number between 1 and 100.
Kid: Is it 40?
D: Higher
Kid: Is it 80?
D: Lower
Kid: Is it 57?
D: How did you guess?

 

Write a Python function that conforms to the following: