3.1507
230/73 = 3.15 (approx).
If you have calculated the value, why then estimate it? If you must, estimate = 3.15.
73
230
73 can be divided by 1 and 73.
230
19.1667
The answer 2, 230 divided by 10 is 23. If you had that answer you are correct
31974 divided by 438 = 73
73 divided to 8103 = 0.009009009009009009
0.0685
The best estimated value is the exact answer since anything else can be improved upon with more effort.
230
7.6667