Or even simpler, just change the print to printf 

my $zmax = 60;    # Maximum depth in your model
my $dz = 0.05;    # Grid spacing in z-direction

for (my $i=0; $i <= $zmax; $i = $i+$dz) {
   printf("%.2f\n", $i);
}

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In reply to Re^3: Wrong calculations in for loop by SuicideJunkie
in thread Wrong calculations in for loop by Anonymous Monk

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