It might also be useful to exclude methods that are inherited from Object.
(Fixnum.public_instance_methods - Object.public_instance_methods).sort
=> [:%, :&, :*, :**, :+, :+@, :-, :-@, :/, :<, :<<, :<=, :>, :>=, :>>, :[], :^, :abs, :abs2, :angle, :arg, :between?, :ceil, :chr, :coerce, :conj, :conjugate, :denominator, :div, :divmod, :downto, :even?, :fdiv, :floor, :gcd, :gcdlcm, :i, :imag, :imaginary, :integer?, :lcm, :magnitude, :modulo, :next, :nonzero?, :numerator, :odd?, :ord, :phase, :polar, :pred, :quo, :rationalize, :real, :real?, :rect, :rectangular, :remainder, :round, :singleton_method_added, :size, :step, :succ, :times, :to_c, :to_f, :to_i, :to_int, :to_r, :truncate, :upto, :zero?, :|, :~]
or maybe more readable:
(Fixnum.public_instance_methods - Object.public_instance_methods).sort.join(" ")
=> "% & * ** + +@ - -@ / < << <= > >= >> [] ^ abs abs2 angle arg between? ceil chr coerce conj conjugate denominator div divmod downto even? fdiv floor gcd gcdlcm i imag imaginary integer? lcm magnitude modulo next nonzero? numerator odd? ord phase polar pred quo rationalize real real? rect rectangular remainder round singleton_method_added size step succ times to_c to_f to_i to_int to_r truncate upto zero? | ~"
