You spend half of your money on a movie ticket. Then you spend half of what you have left to buy a large popcorn. Then you spend half of what remains to buy a small drink. Which expression equals the fraction of money you have left?

Spent half on movie tickets:
Movie Tickets = 1/2
Remaining = 1 - 1/2 = 1/2

Spent half of remaining on popcorn:
Popcorn = 1/2 of 1/2 
Popcorn = 1/2 x 1/2
Popcorn = 1/4
Remaining = 1/2 - 1/4 = 1/4

Spent half on remaining on small drink:
Drink = 1/2 of 1/4
Drink  = 1/2 x 1/4 
Drink = 1/8

Left:
1/4 - 1/8 = 2/8 - 1/8 = 1/8

Ans: 1/8 of the money is left.