I think you have a tiny typo: 103 is not likely?
if you meant 100 then
we need to multiply the original number by 100:
0.04*100=4, so it would appear as if it had 4 mm!
and if you meant 10 (if they typo was supposed to be 10x for example)
then we need to multiply by 10;
0.04*10=0.4 mm!