diff --git a/calculator_f.rb b/calculator_f.rb
new file mode 100644
index 0000000..a852816
--- /dev/null
+++ b/calculator_f.rb
@@ -0,0 +1,76 @@
+
+# Check if the input is a number (thanks stackoverflow)
+def check_number?(x)
+  if x.to_f.to_s == x || x.to_i.to_s == x
+    true
+  else
+    false
+  end
+end
+
+# Check the operation is valid
+def check_operation?(operation)
+  operation_options = ["+","add","-","subtract","*","multiply","/","divide", "^", "exponent","%", "modulo"]
+  if operation_options.include? (operation)
+    true
+  else
+    false
+  end
+end
+
+# Read the first_number
+print "Enter your first number > "
+first_number = gets.chomp
+while !check_number?(first_number)
+  puts "That's not a number"
+  print "Enter your first number > "
+  first_number = gets.chomp
+end
+first_number = first_number.to_f
+
+puts "-----------------------"
+
+print "Enter your operation > "
+operation = gets.chomp
+
+# Read the operation
+while !check_operation?(operation)
+  puts "invalid operation"
+  print "Enter your operation > "
+  operation = gets.chomp\
+end
+puts "-----------------------"
+
+# Read the second number
+print "Enter your second number > "
+second_number = gets.chomp
+while !check_number?(second_number)
+  puts "That's not a number"
+  print "Enter your second number > "
+  second_number = gets.chomp
+end
+second_number = second_number.to_f
+
+# handle division by 0
+if second_number == 0 && (operation == "/" || operation == "divide" )
+  result = "invalid"
+else
+  # handle valid operations
+  case operation
+  when "+","add"
+    result = first_number + second_number
+  when "-", "subtract"
+    result = first_number - second_number
+  when "*", "multiply"
+    result = first_number * second_number
+  when "^", "power"
+    result = first_number ** second_number
+  when "/", "divide"
+    result = first_number / second_number
+  when "%", "modulo"
+    result = first_number % second_number
+  end
+end
+
+# print the formula
+puts "Your formula --> #{first_number} #{operation} #{second_number} = #{result}"