# Excel 2010 calculation inexact

• ### Question

• Hello Everyone,

It is found

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Put 1.01 in one cell (for example in A1).
1.01*1.01*1.01=1.030301.
However if one calculates formula
(1) =A1*A1*A1-A1
(2) =A1*(A1+1)*(A1-1)
(3) =1.030301-A1
(4) =1.030301-1.01

(1),(3),(4) give 0.0203009999999999
(2) gives 0.02030100000000000.

If one uses (2)-(4), then Excel 2010 shows -1.14492E-16.
The calculation can be done as the integer multiplication/subtract and should return the exact result. Only (2) gives the correct answer.

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Can anyone replicate this? Is it a known bug?

Thanks.

mercredi 7 novembre 2012 11:44

### Réponses

• Bonjour,

Regarde ici (have a look here) :

Daniel

• Marqué comme réponse jeudi 8 novembre 2012 10:56
mercredi 7 novembre 2012 12:22

### Toutes les réponses

• Bonjour,

Regarde ici (have a look here) :

Daniel

• Marqué comme réponse jeudi 8 novembre 2012 10:56
mercredi 7 novembre 2012 12:22
• Bonjour,

Pouvons-nous considérer que vous avez résolu votre problème?

N'hésitez pas à revenir et supprimer la réponse marquée si la solution n’est pas correcte. Merci !

Cordialement,

Aurel

jeudi 8 novembre 2012 10:57
• Thanks for the response. As end user, I would consider that this problem at least existed since 2008. Why should I care how Microsoft implemented the above calculations? I could use the `scientific calculator` within accessories to get the correct answer however Excel is giving me the wrong answer. Many banks are using spreadsheet to produce the risk reports. ...
vendredi 9 novembre 2012 03:43
• It'not an "Excel only" defect, it's linked to floating point
calculation used by every computer system. Read the following page :

http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html

Daniel

vendredi 9 novembre 2012 09:23