Answer: First assume that the fractions are all positive.
Next, add 1/2 and 1/2; the sum is 1. Thus, the two fractions must each be smaller than 1/2.
Let's try adding 5/16 and 7/16. Both are smaller than 1/2. Their sum is 12/16, or 3/4, which is less than 1.
Choose a couple other pairs of fractions which are between 0 and 1/2. Then find the sum of each pair. What do you observe about the size of these sums?