2 W-2s from the same employer with different states/wages

I work for one company and received a 4-page W-2 from them (two of the pages being the back sides had the W-2 been printed, so really two W-2s), one for each state I worked in. I am a NJ resident but go to school in PA, so I worked at the NJ location for the majority of the year, and at a PA location in the fall. The first W-2 is normal, box 1 has my total earnings, it says NJ in box 15, and the same amount of money is listed in box 16 as state earnings as the amount in box 1, like any other W-2 I've received. But on the second W-2 there is no information in boxes 1-6, the only information is in the state section (14-20). 

 

The confusion for me is that I originally thought that the reason the federal part is blank is that all my money that is taxed federally was on the first W-2. But like I said before, box 1 and box 16 on the first W-2 are the same, if you add the PA wages, that is more than box 1, so is that money not being taxed federally? On the flip side, if both state wages are supposed to add up to box 1, does that mean that my PA wages are also being taxed in NJ? Neither direction makes much sense, and the total affects what tax bracket I am in so I don't want to make a mistake. 

 

In case I didn't explain it well I'll make a simplified example:

 

W-2 One: Box 1= 7, Box 16=7.

W-2 Two: Box 1=0, Box 16=3. 

So is my total income for the year 7 or is it 10? When I look at my YTD Earnings for the company, it says 7, but when I upload the W-2 to TurboTax, it adds them together and says 10, and if it is 7, does that mean that my income is being double-taxed?