Replies

The distributive property of multiplication tells me that 2(9+3) = 2(9)+2(3) = 18+6 = 24. It is a single expression. It could be 2(a+b) or 2(x+y). The entire expression must be dealt with before the expression is used in the remainder of the equation.

The original poster's question concerned a programmable calculator. Therefore other such calculators are worthy of examination, such as the well-known bc, "an arbitrary precision calculator" which yields the following:

bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'. 
48 / 2 * (9 + 3) 
288

Much of the math in computing is derived from the C language where the Operator Precedence rules have been adopted by ANSI for several decades.

The original poster's question concerned a programmable calculator. Therefore other such calculators are worthy of examination, such as the well-known bc, "an arbitrary precision calculator" which yields the following:

And I haven't even used a calculator yet (physical or PC based)..

Bikk