Question
What are the missing numbers?
7474, 7504, (a)         , 7564, (b)         , 7624
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?
7474, 7504, (a)         , 7564, (b)         , 7624