iPad 2, Numbers - Add row below

I'm creating an invoice sheet that I'd like to add like I do in Numbers in OSX

In Numbers on OSX I just press the ALT-Down Arrow to create a row below the previous product line item.

I'm trying to figure out a way to accomplish this on the ipad 2 using iOS 5 and Numbers

For example, in the image attached, I want to add a productname2 below Product Name Here line.

Thanks