O.O.O. : Order Of Operations

if you want to remember the O.O.O.  just remember this saying...
Please Excuse My Dear Aunt Sally
a         x           u     i        d       u
r         p            l     v        d       b
e        o            t      i                  t
n        n            i      d                 r
t         e            p      e                a
h        n            l                         c
e        t             y                         t
s        s
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