Ruby 2.5.1 number thingy benchmark

_results.log

Warming up --------------------------------------
               maths    50.286k i/100ms
           slice map    34.402k i/100ms
           multi map    13.137k i/100ms
            original    24.600k i/100ms
                gsub    14.685k i/100ms
           all maths    55.759k i/100ms
            readable    14.009k i/100ms
Calculating -------------------------------------
               maths    663.215k (± 2.9%) i/s -      3.319M in   5.008728s
           slice map    446.610k (± 1.9%) i/s -      2.236M in   5.008779s
           multi map    161.509k (± 2.5%) i/s -    814.494k in   5.046579s
            original    310.873k (± 2.8%) i/s -      1.574M in   5.069136s
                gsub    190.076k (± 5.6%) i/s -    954.525k in   5.040161s
           all maths    596.778k (± 4.5%) i/s -      3.011M in   5.055396s
            readable    146.767k (± 5.7%) i/s -    742.477k in   5.074410s

Comparison:
               maths:   663215.2 i/s
           all maths:   596777.9 i/s - 1.11x  slower
           slice map:   446610.2 i/s - 1.48x  slower
            original:   310872.6 i/s - 2.13x  slower
                gsub:   190075.6 i/s - 3.49x  slower
           multi map:   161509.3 i/s - 4.11x  slower
            readable:   146767.2 i/s - 4.52x  slower

number_thingy_bench.rb

Benchmark.ips do |x|
  N = 1326767
  x.report("maths"){ (0...N.to_s.size).step(3).map{ |i| (N/10**i) % 1000 } }
  x.report("slice map"){ N.digits.each_slice(3).map { |a, b = 0, c = 0| a + b * 10 + c * 100 } }
  x.report("multi map"){ N.digits.each_slice(3).map(&:join).map(&:reverse).map(&:to_i) }
  x.report("original"){ N.to_s.reverse.scan(/\d{1,3}/).map(&:reverse).map(&:to_i) }
  x.report("gsub"){ N.to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, '\1,').split(",").map(&:to_i).reverse }
  x.report("all maths"){ (0..Math.log10(N.abs).floor).step(3).map{ |i| (N/10**i) % 1000 } }
  x.report("readable"){ N.digits.each_slice(3).map { |a| a.join.reverse.to_i } }
  x.compare!
end