100.77 round to the nearest tenth of a square mile

The tenth place is the one just to the right of the 0.  This means that we have to look at the hundreths place which is 2 places to the right of the 0.  If the number is  greater than or equal to 5 then we round  up.  The number in the hundreths place is 7, which is above 5 we round the tenths place up to 8.

This would make your answer 100.8

1.3 and 1 1/3 are both closest to 1. hope this ; )