A ruby class to calculate English Gematria. This example uses a mispar hechrachi style correspondence table, but that can easily be swapped out for another table. Class supports raw conversion to number, mapping (breakdown of numbers), and reduction to a single digit (mispar katan mispari). ***Scroll down to see it in action.

gematria.rb

# Ruby class to calculate English Gematria
class Gematria < Struct.new(:text)
  CORRESPONDENCE_TABLE = { # applies `mispar hechrachi` method to English alphabet (http://www.inner.org/gematria/fourways.php)
    a: 1,   b: 2,   c: 3,   d: 4,   e: 5,   f: 6,   g: 7,   h: 8,   i: 9,
    j: 10,  k: 20,  l: 30,  m: 40,  n: 50,  o: 60,  p: 70,  q: 80,  r: 90,
    s: 100, t: 200, u: 300, v: 400, w: 500, x: 600, y: 700, z: 800
  }

  def mapped
    text.each_char.map { |c| lookup_char c }
  end

  def converted
    mapped.inject(:+)
  end

  def reduced # delegates to private recursive function
    do_reduction_on converted
  end

  private
  def do_reduction_on(number)
    if number < 10
      number
    else
      do_reduction_on number.to_s.each_char.map(&:to_i).inject(:+)
    end
  end

  def lookup_char(char) # find lowercase letter, characters not in the table have no value
    CORRESPONDENCE_TABLE.fetch(char.downcase.to_sym, 0)
  end
    
end

gematria_example.rb

# Example usage
name = Gematria.new("Adam")
name.converted          # => 46
name.mapped.join(" + ") # => "1 + 4 + 1 + 40"
name.reduced            # => 1

gematria = Gematria.new("Gematria is fun!")
gematria.converted      # => 818
gematria.mapped         # => [7, 5, 40, 1, 200, 90, 9, 1, 0, 9, 100, 0, 6, 300, 50, 0]

alphabet = Gematria.new("abcdefghijklmnopqrstuvwxyz")
alphabet.converted == 4095 # => true