I think you are missing something, what expression?
If you mean the • dot, it means multiplication.
60
2 and 30
30
2 and 15
15
3 and 5
96
8 and 12
circle for 8 is 2 and the square is 4
circle for 12 is 2 and the last circle is also 2
6/10 of an inch= 0.6
7 (times) 0.6 (equals) 4.2
