How do you use prices like 2.3e-7 and 1e-8?

Iv'e bought some assets listed for 2.3e-7 and seen others going 1e-8 and such, anyone know much about using these prices?, I find that if I try to change these numbers like using 2.2e-7 does not work? or maybe it's because I got a C* in maths lol :)