5/68
5 can go into 68 13 times with a remainder of 3
So we add a decimal point and a zero.
Carry the 3 and zero down making 30
5 can go into 30 6 times making the answer 13.6
The best answer is 1.435 ·103 because while they both are really small for a rail road track that one is bigger. the final answer for that is 147.805mm.
