The number 2.85 can be writen using the fraction 285/100 which is equal to 57/20 when reduced to lowest terms.
It is also equal to 2 17/20 when writen as a mixed number.
You can use the following approximate value(s) for this number:57/20 =~ 2 6/7 (if you admit a error of 0.250627%)2.85 =~ 2 5/6 (if you admit a error of -0.584795%)2.85 =~ 3 (if you admit a error of 5.263158%)