JSS:
"You say :
Room cost = £25.
£9 paid by each man = £27.
The EXTRA £2 was stolen by the Bell Boy.
So we agree if each man paid £9 (3 x 9) = £27.00
The £2.00 stolen by the bell boy = £2.00
Total = £29.00.
Therefore you agree with me!
Where's the missing pound?"
You want to subtract the 2 from 27 instead of adding the 2. Then you get the remainder, which is 25 (the amount owed to the hotel in the first place).
You could do this with pennies (or any small object). Count out 30 pennies. Pretend the men are on the left, the hotel is on the right and the bellboy is in front of you.
Start with 30 pennies on the men's side.
1. Transfer the 30 pennies to the right (hotel).
2. Transfer 5 pennies from the hotel to the bellboy.
3. Transfer 3 pennies from the bellboy to the men.
All 30 pennies are still there. The bellboy has 2, the hotel has 25 and the men have 3. That equals 30.