How to make the calculator be chained? How to write stacks in code? How to display the last prime number?

Question

ruby

you need to be able to chain actions

i.e.

2
+
2
4
+
5
9
, etc., and work with the stack (the first container entered - the last one left), and so that the calculator could display the last prime number (and write it to the stack)
Calculator has started

3

primes

10

7 // displays the last prime number, writes all numbers to the stack

pop

7

pop

5

pop
Error

I don't understand what and how and where to enter. Please help me (
code:

print 'Type number: '
first_number = gets.strip.to_i
print 'Type operation: '
operation = gets.strip
if %w[+ - * / ** %].include? operation
  print 'Type second number: '
  second_number = gets.strip.to_i
  puts first_number.send(operation, second_number)
elsif %w[sqrt sin cos tan exp].include? operation
  puts Math.send(operation, first_number)
else
  puts 'error'
if fibonacci(n)
  n < 3
        1
  else
        fibonacci(n - 1) + fibonacci(n - 2)
        (1..16).each {|n| puts "#{fibonacci(n)}, "}
puts "..."
    end
end



# Ячейка пам¤ти, не сбрасывается при рестарте калькул¤тора
memory = 0
while true
  puts "Calculator has started"
  print 'Type number: '
  result = gets.strip.to_i
 
  while true
    print 'Type operation: '
    operation = gets.strip
    break if operation == ""
 
    if operation == 'mw'
      memory = result
    elsif operation == 'mr'
      result = memory
    else
      print 'Type number: '
      second_number = gets.strip.to_i
    end
 
    if %w[+ - * / ** %].include? operation
  print 'Type second number: '
  second_number = gets.strip.to_i
  puts first_number.send(operation, second_number)
elsif %w[sqrt sin cos tan exp].include? operation
  puts Math.send(operation, first_number)
else
  puts 'error'

    
      end
    end
    print 'Result: '
    puts result
  end

Answer 1

https://ru.m.wikipedia.org/wiki/%D0%9E%D0%B1%D1%80...