I never really considered it much, but there are apparently 6 different ways to round. Here’s a thread on stackexchange. Apparently most computer rounding is to the nearest even number!
Looks like Desmos uses the convention of rounding halves “up” or the positive direction, while you’re looking for rounding away from 0. You could make your own function.
r_{ound}(n, d) = \sign(n)(\round(\abs(n),d))
There may be someone more knowledgeable at support.desmos.com which handle the graphing calculator.