diff --git a/calculator.rb b/calculator.rb
new file mode 100644
index 0000000..485d5ba
--- /dev/null
+++ b/calculator.rb
@@ -0,0 +1,101 @@
+# Methods for each arithmetic operator
+def add(num_one, num_two)
+  puts "#{num_one} + #{num_two} = #{num_one + num_two}"
+end
+
+def subtract(num_one, num_two)
+  puts "#{num_one} - #{num_two} = #{num_one - num_two}"
+end
+
+def multiply(num_one, num_two)
+  puts "#{num_one} * #{num_two} = #{num_one * num_two}"
+end
+
+def divide(num_one, num_two)
+  puts "#{num_one} / #{num_two} = #{num_one / num_two}"
+end
+
+def modulo(num_one, num_two)
+  puts "#{num_one} % #{num_two} = #{num = num_one / num_two
+         total = num_two * num
+         remainder = num_one - total}"
+end
+
+def exponent(base_num, exp_num)
+  result = 1
+  exp_num.times do
+    result *= base_num
+  end
+  puts "#{base_num}^#{exp_num} = #{result}"
+end
+
+# Welcome message to user
+puts "Welcome to the Calculator program! Which operator would you like to use?
+1. add(+)
+2. subtract(-)
+3. multiply (*)
+4. divide (/)
+5. modulo (%)
+6. exponent (** or ^)"
+
+puts "Please choose one operator(name or symbol):"
+
+# Stores user's input as one of the operators or prints a message telling them to enter a valid operator
+while users_operator = gets.chomp.upcase
+  case users_operator
+  when "ADD", "+"
+    break
+  when "SUBTRACT", "-"
+    break
+  when "MULTIPLY", "*"
+    break
+  when "DIVIDE", "/"
+    break
+  when "MODULO", "%"
+    break
+  when "EXPONENT", "**", "^"
+    break
+  else
+    puts "Invalid operator. Please enter a valid operator in order to continue: "
+  end
+end
+
+puts "Please enter a number:"
+
+# Checks and validates user input. If input is not an integer, an exception is thrown and prompts the user to enter a valid number
+begin
+  num_one = Integer(gets.chomp) # Question: Is there a way to accept both integers and floats from the user? Would this require conditional statements?
+rescue
+  puts "Invalid input. Please enter a valid number: "
+  retry
+end
+
+puts "Please enter another number:"
+
+begin
+  num_two = Integer(gets.chomp)
+rescue
+  puts "Invalid input. Please enter a valid number: "
+  retry
+end
+
+# Performs calculations based on user input
+if users_operator == "ADD" || users_operator == "+"
+  add(num_one, num_two)
+elsif users_operator == "SUBTRACT" || users_operator == "-"
+  subtract(num_one, num_two)
+elsif users_operator == "MULTIPLY" || users_operator == "*"
+  multiply(num_one, num_two)
+elsif users_operator == "DIVIDE" || users_operator == "/"
+  if num_two == 0 # If user enters 0 as the second number, an error message is printed and reprompts the user for a greater input
+    puts "You cannot divide by 0! Please enter a number greater than 0: "
+    num_two = gets.chomp.to_i
+    divide(num_one, num_two)
+  else
+    divide(num_one, num_two)
+  end
+elsif users_operator == "MODULO" || users_operator == "%"
+  modulo(num_one, num_two)
+elsif users_operator == "EXPONENT" || users_operator == "**" || users_operator == "^"
+  exponent(num_one, num_two)
+end