Question
What are the missing numbers?
7423, 7433, (a)         , 7453, (b)         , 7473
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 numbers?
7423, 7433, (a)         , 7453, (b)         , 7473