I have a question, for example.
we define real a = 10.0014 and real b = 0.0000123456
then we compute a+b by using FreeFem
we obtain a+b = 10.0014, however the ture is 10.0014123456

so how can we avoid such error during the use of FreeFem. I encounter such error. if t = 10.0014 and dt = 0.0000123456, then the time step cannt be moved into a new time.

Hi, thanks a lot.
i define real d = 10.0012 and find that d != c. So when performing operations, you mean the real value of c is 10.0012123456 not 10.0012 ?