Known bug in Excel????

[mortgageman]

According to math rules 2^3^2 should equal 2^9 (you go right to left in this case). Excel gives 64. Is this a known bug?

Gene Klein

 

[mortgageman]

Gene

Yes.

2+3x4 is less clear than 2+(3x4).

Why? Why is 2+3x4 different then 2^3^4?

Gene Klein

 

[Norie]

Gene

I don't understand.

How is it connected to 2^3^4?

 

[Scott Huish]

Because multiplication has precedence over addition.

 

[xenou]

Why is 2+3x4 different then 2^3^4?

2+3X4 involves two different operands with different levels of precedence so its different from 2^3^4 for that reason. However, the issue of "clarity" is a general one related to programming practices or, in the case of Excel, writing formulas. It is generally recommended to use parentheses to make your intentions clear. But some individuals may disagree and choose not to do so - assuming, of course that they know the the rules for the order of operations. As has been pointed out, there's nothing you can do about these rules vis-a-vis whatever computing package you are using - you have to use them as they are in order to get the correct results.

I don't see anything odd about this. You start out in mathematics even in a traditional setting learning many rules and conventions - some of which at some point were themselves arbitrarily decided. The computer age introduced a set of new conventions is all

Edit:
Though in the world of computing there's many wrinkles - every programming textbook for any programming language will have a chapter on the order of operations and you have to learn them as computing expression can be quite complex involve many kinds of operators, not just mathematical ones --> i.e. assignment operators, comparison operators, bit operators. For those of us who work closing with computers, this is all just part of the job. Clarity is valued because one operator in the wrong place could cause serious errors in the result, and such errors can be difficult to trace.

 

[Norie]

What about 2 3 + 4 x ?

or should that be 2 3 4 x + ?

 

[Scott Huish]

I don't think Excel can handle Reverse Polish Notation.

 

[Kenneth Hobson]

I like reverse polish notation in the HP48SX. In the context of this thread, I used HP48SX and HP48GX in scientific and equation modes.

Here is a summary of my tests:

-2^2 2^3^2 Program Note
-4 512 Math Rules
4 64 Excel
-4 64 Lotus123
-4 64 QuattroPro
-4 512 http://www.soople.com/soople_intcalchome.php Google Calculator - Adds ()'s to formula after result
-4 64 HP48SX/GX and some emulators Scientific Mode
-4 512 HP48SX/GX and some emulators Equation Mode
4 64 TI-36X Solar
-4 64 PrefectScript
-4 512 R
-4 512 SAS
4 64 vbs
-4 64 vba
-4 512 vb.net

 

[Norie]

Kenneth

Why all the minuses?

 

[Scott Huish]

I agree -4 is the incorrect answer for -2 squared. It should be 4. (-2 * -2 = 4)

 

[xenou]

4 64 vbs
-4 64 vba
-4 512 vb.net

Rather amusing that three languages with vb in their name are none alike.