Give or take means approximately, allowing a little either way. Ten years, give or take, give or take a mile, give or take a few.
It comes after the figure rather than before it, which is what makes it sound so casual. Give or take a few is the standard way of admitting you counted roughly.
1phrasegive or takeApproximately, allowing a little either way.
“The house is two hundred years old, give or take.”
give or take is an approximation.
From the plain sense of allowing a little to be given or taken from a figure.
c. See cite below.
Etymology from Wiktionary, CC BY-SA
Practised in Small Talk & Everyday Phrases