thank you all for your help but all of you said that the fixed point representation is more common and easier . so why in many books and also many videos on youtube say that the floating point representation is the more common way ? i'm really getting lost now can anyone please tell me a summary or if there is a table including all the ways of representing negative and real numbers ? and which one is better or which one is used nowadays ? and how can i decide which way i can use ? is it depending on the computer and on the number ?