Consolidate two data sets

Hi all, how do you consolidate two data sets to compile one summary table which adds together the number for each product in each month. The consolidated table would contain the same column headings with the added number in column three. Is there a way of automating this process (Pivot?Consolidate?). Thank you

Product Month Number
a jan 654
b feb 234
c mar 123
d apr 543
e may 765
f jun 876
g jul 345
h aug 567
i sep 532
j oct 111
k nov 423
l dec 776


Product Month Number
a jan 123
b feb 234
c mar 654
d apr 564
e may 556
f jun 234
g jul 987
h aug 765
i sep 123
j oct 443
k nov 554
l dec 765

OK i have attached the spreadsheet. Solution would assume that the data in the underlying data sets is not sorted and so a simple sum of the reference cells would not be appropriate.

I tried that but I can't get it to work as my data is not in cross tab format (it's essentially a list not a table)