Fractions: Sums of halves
Word problem
A snail is moving from one end towards the other on a line that is one metre in length. During the first hour, it moves half the length of the line. During the second, it moves half the length of the line remaining. During the third, it moves half the length of the line remaining, and so forth. How long a distance does the snail move during the first 24-hour period?