Which is the best estimate for the sum of 1/12 + 3/8

1/12 + 3/8   LCD is 24    9/24 + 2/24   = 11/24 or 0.46                                         

The answer would 1/2
to get a good estimate, you should use benchmarks. benchmarks can be 0,1/2. or 1
round 1/12 to 0 and 3/8 to 1/2.
when you add 0 and 1/2, you get 1/2.
that would mean the best estimate would be around 1/2.
hope this helps! :)