[R] how to add tables of different dimensions

[Henrik Kallberg]

Hi all!
I'm stuck with this "easy" problem. I have two tables  (a and b) which i would like to add. table a looks like:
a
var1 var2
3      4 
and table b looks like:
b
var1
10
I would like this result: c<- a+b
c
var1 var2
13    4
Best regards Henrik Källberg