after
                 big      6.596M (? 7.8%) i/s -     32.708M in   4.995933s
before
                 big      4.264M (? 5.7%) i/s -     21.237M in   4.994988s

after
                 big      8.865M (? 2.6%) i/s -     44.215M in   4.991349s
before
                 big      4.704M (? 4.4%) i/s -     23.487M in   5.004868s

require 'benchmark/ips'

Benchmark.ips do |x|
  x.report('fix') { 5.succ }
  x.report('big') { 500000000000000000000000000000000000000000000000000000000000000000000000004.succ }
end