Educational Stuff

ROUND OFF vs ROUND UP
The difference is that:
ROUND OFF Means: to bring an end to something. For example; they rounded off their six-match tour with a brilliant victory.
ROUND UP Means: to find and arrest people. It also means to bring animals or people together in one place for a particular purpose. For example; I used to help round up the cows at milking time.
Having known these, one will see that there is a clear difference between these two phrases as one cannot be used in place of other, they are not related.
But, sometimes, people make mistake and use the latter in place of the former, i.e. when they mean "bringing something to an end", they use "ROUNDING UP instead of ROUNDING OFF.
Always take note of the phrases while using them.