Block that outputs the input after rounding it to n
digits.
For example,
n = 0
to round to the nearest integer,
n = 1
to round to the next decimal point, and
n = -1
to round to the next multiple of ten.
Hence, the block outputs
y = floor(u*(10^n) + 0.5)/(10^n) for u > 0, y = ceil(u*(10^n) - 0.5)/(10^n) for u < 0.