diff --git a/calculator.rb b/calculator.rb
new file mode 100644
index 0000000..fa3e9a1
--- /dev/null
+++ b/calculator.rb
@@ -0,0 +1,83 @@
+puts "Welcome to the Ruby Calculator!"
+
+operator = ""
+# valid operators
+operators = [
+  "add", "+", "1", 
+  "subtract", "-", "2", 
+  "multiply", "*", "3", 
+  "divide", "/", "4",
+  "exponent", "**", "5",
+  "modulo", "%", "6"
+]
+
+# prompt user for operator until they enter a valid option
+until operators.include?(operator)
+  puts "Please choose an operation from the list (name, symbol, or number):
+  1. add(+)
+  2. subtract(-)
+  3. multiply(*)
+  4. divide(/)
+  5. exponent(**)
+  6. modulo(%)"
+  operator = gets.chomp.to_s.downcase
+end
+
+# update operator to operation to use in user prompt
+case operator
+when "add", "+", "1"
+  operator = "addition"
+when "subtract", "-", "2"
+  operator = "subtraction"
+when "multiply", "*", "3"
+  operator = "multiplication"
+when "divide", "/", "4"
+  operator = "division"
+when "exponent", "**", "5"
+  operator = "exponent"
+when "modulo", "%", "6"
+  operator = "modulo"
+end
+
+# validate that user input is numeric
+def validate_number(num)
+  while num.to_i.to_s != num.strip
+    puts "#{num} is not a valid number! Enter a new number: "
+    num = gets.chomp
+  end
+  return num
+end
+
+# prompt user for number inputs
+puts "You chose #{operator}! Enter your first number: "
+num1 = gets.chomp
+num1 = validate_number(num1)
+
+puts "Enter your second number: "
+num2 = gets.chomp
+num2 = validate_number(num2)
+
+# display result based on operator
+case operator
+when "addition"
+  puts "#{num1} + #{num2} = #{num1.to_i + num2.to_i}"
+when "subtraction"
+  puts "#{num1} - #{num2} = #{num1.to_i - num2.to_i}"
+when "multiplication"
+  puts "#{num1} * #{num2} = #{num1.to_i * num2.to_i}"
+when "division"
+  # prevent user from entering 0 for num2 during division
+  if num2 == "0"
+    puts "You cannot divide by 0!"
+  else
+    puts "#{num1} / #{num2} = #{num1.to_i / num2.to_i}"
+  end
+when "exponent"
+  formula = ""
+  num2.to_i.times do |i|
+    formula += "#{num1} * "
+  end
+  puts "#{formula.chomp(" * ")} = #{num1.to_i ** num2.to_i}"
+when "modulo"
+  puts "#{num1} % #{num2} = #{num1.to_i % num2.to_i}"
+end