On further inspection, the jasonwoof code is quite a bit simpler not only because it has a better approach (which it does!) but also because it leaves out the checks for 0 and off-by-one. So it crashes on 0 and gives the wrong answer for 6, saying 3 when the answer correct to two places is 2.45. You can correct the wrong answers with the same dup dup * n @ > if 1- then business that I was using, assuming you want floor(sqrt(n)) instead of, say, round(sqrt(n)) or ceil(sqrt(n)).
