Linux: Add numbers in a column in a file

In windows we use Excel to add all the numbers in a column. But how about Unix/Linux?
We encountered such an requirement and we got the answer too.
Actually solution in much more simpler than the problem..!

Mission accomplished by 'awk' command. Its merely a very powerful and useful command.
Here is an example for it:


I've a file num.test with below values in it. 

# cat num.test

1

2

3

4

5

Now that I want to add all these values in a single command. Here's the answer:

#awk '{s+=$1} END {print s}' num.test

15

Just simple as that!