I wonder how you'd handle it. For 2,345,000 would you rather write 2.234 x 10^6 2.234M 2.234e6 Except for exams I never use anything but the e...-Notation. Therefore: 2.234e6. Using the SI Prefixes I just feel not capable of because I hardly can remember the value of any besides the few standard ones like m,k,M,µ..., no matter how many times I try to remember them. Writing ... x10^... however feels way to elaborate. What do you use? What is chiefly accepted by the physicists community?