My complete test

def test(b:int) -> int:
    """
    `//` does "floor division", meaning it performs the division and then
    does a true floor operation - unlike C and Python2 which do "integer"
    division that merely truncates the remainder.
    """
    return (b + 16383) // 16384

def foo(b:int) -> int:
    """
    Nothing to explain here, just the second of your three expressions.
    """
    return ( (b - 1) // 16384) + 1

def quest(b:int) -> int:
    """
    "An upside-down ceiling is a floor" is the advice that led me to this;
    in Python3 `-(-x//y)` is ceil(x/y) because of the aforementioned
    "floor division" that will result in e.g. `-1//2` = `-1` and then a
    correcting inversion gives `-(-1//2) = -(-1) = 1 == ceil(1/2)`.
    """
    return -(-b // 16384)


# this checks for any differences in the outputs by testing with each integer
# on the interval from 0 (inclusive) to 163840 (exclusive), because
# `NOT(x = y) or NOT(x = z)` is equivalent to `NOT( x = y AND x = z)` which by
# transitive property covers all cases where any one output is different.
for i in range(163840):
    if test(i) != quest(i) or test(i) != foo(i):
            print("i=", i, " test(i)=", test(i), " quest(i)=", quest(i), " foo(i)=", foo(i), sep='')
            break

# At this point, nothing is output, meaning the entire loop was executed without
# finding any differing outputs.