How do I create a Pivot Table in Numbers 3.2?

Question

I'm new to Numbers and currently using Numbers 3.2.

I already have an idea of how to use SUMIFS to create Pivot Tables in Numbers, but I'm still looking for a better way to generate the column & row names.

For example, if I have:

A       B       C
red     left    2
red     left    3
green   left    4
green   right   4

I want to be able to get:

        red     green   all
left    5       4       9
right   0       4       4
all     5       8       13

When the dataset is 2x2, I can simply retype the column & row names. But if the dataset is 20x10,000...

I read that they have this category feature in Numbers '09, but how do I implement it in Numbers 3.2?