diff --git a/calculator.rb b/calculator.rb
new file mode 100644
index 0000000..1140c29
--- /dev/null
+++ b/calculator.rb
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+# Program that acts like a calculator
+
+# Display welcome message and instructions
+puts "Welcome to the calculator program! Which operation would you like to use?"
+puts "\n1. add(+) \n2. substraction(-) \n3. multiply(*) \n4. divide(/)"
+puts "\nPlease choose one operator(name or symbol):"
+
+acceptable_operation = %w(1 add + 2 subtract - 3 multiply * 4 divide /)
+
+# Methods for operations
+def addition (x, y)
+  result = (x + y)
+end
+
+def substraction (x, y)
+  result = (x - y)
+end
+
+def multiplication (x, y)
+  result = (x * y)
+end
+
+def division (x, y)
+  result = (x / y)
+end
+
+# Methods for verification
+def verify_operation(data_to_verify, data_acceptable)
+  until (data_acceptable.include? data_to_verify) == true
+    puts "Option not accepted. Please enter the symbol or name of the operation."
+    data_to_verify = gets.chomp
+  end
+  data_to_verify
+end
+
+def verify_number(data_to_verify)
+  until (Integer(data_to_verify) rescue nil) != nil
+    puts "Input not accepted, please enter a number:"
+    data_to_verify = gets.chomp
+  end
+  data_to_verify.to_f
+end
+
+# Prompt user to select an operation, two numbers and verify the input
+puts "What operation would you like to do?"
+operation = gets.chomp.downcase
+operation = verify_operation(operation, acceptable_operation)
+
+puts "Enter in your first number"
+first_number = gets.chomp
+first_number = verify_number(first_number)
+
+puts "Enter in your second number"
+second_number = gets.chomp
+second_number = verify_number(second_number)
+
+# Calculate operation user requested
+case operation
+  when "add", "+", "1"
+    puts "You have chosen to add " "#{first_number} with #{second_number}"
+    result = addition(first_number, second_number)
+  when "substraction", "-", "2"
+    puts "You have chosen to substract " "#{first_number} with #{second_number}"
+    result = substraction(first_number, second_number)
+  when "divide", "/", "3"
+    puts "You have chosen to divide " "#{first_number} by #{second_number}"
+      if second_number == 0
+        puts = "Cannot divide by zero"
+      elsif first_number == 0
+        result = 0
+      else
+        result = division(first_number, second_number)
+      end
+  when "multiply", "*", "4"
+    puts "You have chosen to multiply " "#{first_number} with #{second_number}"
+    result = multiplication(first_number, second_number)
+  else 
+  puts "You have made an invalid choice"
+end
+
+# Display operation result with two decimals
+puts result.round(2)
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