an interface that allows basic calculations with strings

literal_calculation.rb

%i(one two three four five six seven eight nine ten).each_with_index do |num_literal, i|
  define_method(num_literal) do |block = nil|
    block ? block.call(i + 1) : i + 1
  end
end

def plus(second)
  lambda { |first| first + second }
end

def minus(second)
  lambda { |first| first - second }
end

def times(second)
  lambda { |first| first * second }
end

def devide(second)
  lambda { |first| first / second }
end