How to i disable rounding off in calc(libreoffice 5.1.6.2)?

calc starts rounding off after the 78th cell(e.g. a78) and i don’t want that. i have a calc file for the fibonacci sequence that i created and want the entire, correct sequence down to the last columnar cell. how can i do this? i’m using ubuntu 16.04. thanx in advance.

What is the order of magnitude of those values? If the value cannot be exactly mapped to double, then it will be inevitably rounded. See Floating-point arithmetic - Wikipedia

Verify the option Menu/Tools/Options/LibreOffice Calc/Calculate - Precision as show