Wiktionary
round off
vb. 1 To change the shape of an object to make it more circular. 2 (context mathematics English) To change a number into an approximation having fewer significant digits. 3 To complete or finish something.
WordNet
Usage examples of "round off".
He'd been after it for years-wanted it to round off his own place.
The carbine's barrel slammed the roof support, jarring the round off wildly into the empty night.