The Number Hotel
A hundred rooms on ten corridors — and no door after 49, which is exactly why the tens digit changes.
About this tool
Every room in the hotel is a number from 0 to 99, and every corridor carries its tens digit: every room on corridor 4 is a forty-something, so the number on the elevator indicator and the tens digit are not merely alike — they are the same numeral.
One step takes you one door along. The elevator takes you a whole corridor up or down and always leaves you at the same door, so the ones digit never moves. And the corridor really ends: after room 49 there is no door at all, and what carries on is the stairs, which climb and then run the whole width of the hotel back to the first door of the next corridor.
You can only read the doors on the corridor you are standing in, so the elevator always sets the class down somewhere they have to say out loud before they can check it. Nothing is scored, nothing is timed, and nothing is ever marked right or wrong.
How to use it in class
- Project the hotel and read the lit corridor together before touching anything. Ask what all those numbers have in common.
- Step along one door at a time and let the class discover for themselves that after room 49 there is no door — the wall was drawn there from the start.
- Take the stairs and follow the whole journey back to the beginning of the new corridor. Ask why a single step cost so much walking.
- Call the elevator while the corridor above is still dark, and ask the class to say the room before the doors light up.
Classroom ideas
- A two-minute routine: pick a room, walk there, and ask how many steps are left before the corridor ends. The answer is always what is left to the next ten.
- Ride the elevator four or five times with the corridor dark each time, and let the class notice on their own that the door never changes — only the corridor does.
- Before taking a single step, ask where room 40 will be and let the class commit. Then walk until you meet the wall.