Brewing Classic Styles Questions

Hoping someone can help me out with the partial boil instructions in Brewing Classic Styles. When I'm looking at the instructions I don't understand where the ppg numbers are coming from. Are these numbers going to be the same for all steeping grains? If not where can I get these numbers for different grains? Looking forward to using these recipes but need some clarification first. Thanks for any help!

Check out https://www.homebrewtalk.com/wiki/index.php/Malts_Chart
The pppg figure is the potential without the 1.0 in front of it.
Alternatively, download Promash. It doesn't expire in 30 days.

-a.