irb(main):012:0> a.class => Bignum irb(main):013:0> a = 2 ** a (irb):13: warning: in a**b, b may be too big => Infinity irb(main):014:0> a.class => Floatirb(main):012:0> a.class => Bignum irb(main):013:0> a = 2 ** a (irb):13: warning: in a**b, b may be too big => Infinity irb(main):014:0> a.class => Float