Mathematica How Can Mathematica Calculate the Digital Sum of a Number in Base 10?

[amcavoy]

Which command in Mathematica will give me the sum of the digits of a number in base 10? Thanks.

 

[Pengwuino]

So you want it to give you something like this:

Input: 380234
Output: 20
Input: 32138
Output: 17

?

 

[amcavoy]

Yes, exactly. Do you know how that is done?

 

[dav2008]

Is this what you are looking for: http://mathworld.wolfram.com/DigitSum.html ?

 

[amcavoy]

I had already found that; nothing happens when I plug that into Mathematica. I entered:

s[3^14, 10] := Plus @@ IntegerDigits[3^14, 10]

and then nothing came out. Is this the correct way to enter it? For this example I was trying to compute the sum of the digits of 3¹⁴ in base 10. Thanks.

 

[Tide]

That's because you're attempting to define a "function" and haven't asked Mathematica to do anything with it.

For a quick answer, just copy and paste the right side into an input line and evaluate it.