Estimate by rounding the fractions:
15/16 is 1/16 short of being 1, so round 15/16 to 1
7/8 is 1/8 short of being 1 so round 7/8 to 1
7/16 is 1/16 short of being 1/2, so round 7/16 to 1/2
Now add the three: 1 + 1 + 1/2 = 2 and 1/2
Estimating the 3 lengths would be 2 and 1/2 miles.
