diff --git a/coin.rb b/coin.rb
index 9cec6ce..52a170b 100644
--- a/coin.rb
+++ b/coin.rb
@@ -185,7 +185,7 @@ loop do
 
     $mathproblem_op1 = rand(10..150)
     $mathproblem_op2 = rand(10..150)
-    $mathproblem_operator = rand(1) == 1 ? "+" : "-"
+    $mathproblem_operator = rand(2) == 1 ? "+" : "-"
 
     # send the math problem
     bot.send_message(ENV['BOT_CHANNEL'], "Solve the following for #{MATH_PROBLEM_COIN_GAIN} coins: `#{$mathproblem_op1} #{$mathproblem_operator} #{mathproblem_op2}`")