ceil

        # Rational.ceil

(from ruby core)
---
    rat.ceil([ndigits])  ->  integer or rational

---

Returns the smallest number greater than or equal to `rat` with a
precision of `ndigits` decimal digits (default: 0).

When the precision is negative, the returned value is an integer with at
least `ndigits.abs` trailing zeros.

Returns a rational when `ndigits` is positive, otherwise returns an
integer.

    Rational(3).ceil      #=> 3
    Rational(2, 3).ceil   #=> 1
    Rational(-3, 2).ceil  #=> -1

      #    decimal      -  1  2  3 . 4  5  6
      #                   ^  ^  ^  ^   ^  ^
      #   precision      -3 -2 -1  0  +1 +2

    Rational('-123.456').ceil(+1).to_f  #=> -123.4
    Rational('-123.456').ceil(-1)       #=> -120