How would you expect a standard calculator to work?

[FONT=&quot]Hey guys… I was thinking of developing a free online calculator in flash.[/FONT]
[FONT=&quot]It would be a standard calculator with basic functions like “+”, “-”, "" etc. and an advanced calculator with more functions which would be similar to the scientific pocket calculator.[/FONT]
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[FONT=&quot]And I have a dilemma regarding the standard calculator. It’s about the way it does the calculations.[/FONT]
[FONT=&quot]How would you expect a basic calculator (not an advanced one) to calculate this expression:[/FONT]
[FONT=&quot]1+2
3 equals 7 or 9?[/FONT]
[FONT=&quot]On paper the result is clearly 7 but basic pocket calculator calculates the expression in line, unaware of the higher priority operators and give you 9 as a result to the expression above.[/FONT]
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[FONT=&quot]In the advanced version of the online flash calculator this expression would equal 7 but I have doubts about what people expect from a basic calculator.[/FONT]
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[FONT=&quot]So what’s you’re take on this?[/FONT]