take the smallest value of a measurement for example if it was 10.5 you take the 0.5 and make it the smallest it can be 0.1/2 =0.05 which is your absolute error. Then you put your absolute error/actual measurement x 100, which in this case would be 0.05/10.5 x 100 =0.476%oh for std maths, how do we do percentage error?
it was one of the things I got wrong in trials but I cant for the life of me remember how to do it