Question
What are the missing digits?
  1. S
  2. T
   3 T 6 6
+    3 S 3
   4 1 1 9

2 m
(a)

Click button first when a symbol is required. X

(b)

Click button first when a symbol is required. X

What are the missing digits?
  1. S
  2. T
   3 T 6 6
+    3 S 3
   4 1 1 9