Log is not being evaluated inside Grid [closed]

My command is:

Grid[{{N, logN!, N log N - N}, {10, Log[10!], 10 Log[10] - 10}}, Frame -> All]


In the second row of the grid, the function Log[] is not being evaluated.

Please let me know what is going wrong.

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Hi Omar. How about N@Log[10]? –  cormullion Sep 11 '13 at 15:27
The log of 10 is Log[10] not 2.3025 just like the square root of 2 is Sqrt[2] and not 1.414. Take some time to let that think in. Mathematica likes to keep things exact as long as it can and as long as it makes sense. –  Sjoerd C. de Vries Sep 11 '13 at 17:01

closed as off-topic by Szabolcs, Artes, Sjoerd C. de Vries, rm -rf♦Sep 11 '13 at 17:56

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – Szabolcs, Artes, Sjoerd C. de Vries, rm -rf
If this question can be reworded to fit the rules in the help center, please edit the question.

Mathematica never returns inexact answers when you give it exact expressions. If you append a dot to a number it is considered approximate, so Mathematica will calculate approximate answers. Otherwise it will just return a symbolic expression. N asks Mathematica to treat all numbers as approximate.

N@Grid[{
{"N", "log N!", "Nlog N - N"},
{10, Log[10!], 10 Log[10] - 10}},
Frame -> All
]


or using dots:

Grid[
{
{"N", "log N!", "Nlog N - N"},
{10, Log[10.!], 10 Log[10.] - 10}
}, Frame -> All]


The approximated Stirling's approximation in the last column, I suppose.

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The first sentence has an exeption(s?) unfortunatelly :) mathematica.stackexchange.com/q/16282/5478 –  Kuba Sep 11 '13 at 15:40
@Kuba I might add a source later. I don't think there are any intentional exceptions because I'm pretty sure it says exactly what I said in "Power Programming with Mathematica" :) –  Pickett Sep 11 '13 at 15:43
I think your answer is good. It is just a deviation in non related case :) But worth to know. –  Kuba Sep 11 '13 at 15:43