To show the difference in running time between a routine which includes the option numeric versus one that does not include this option, we iterate over a non-trivial mathematical expression and check the elapsed CPU time.
SmallExample := proc ( ) local total; option numeric; total := 0; for i from 1 to 10000 do total := total * (mod (i, 50)) - log(i) + sqrt(i); od; return(total); end: