I'm planning on trying the Norwich sourdough  today. The recipe makes a couple large loaves and I want to just make one (half recipe). I'm new to the baker's percentage and figuring in a 100% starter has me unsure of my math. Can I really just halve every weight measure? When I did this I still got the 65% hydration of the original recipe. For future reference, can you confirm this is the right approach?
Add together the flours
Add those to half the sourdough weight (since it's 50% flour)
That gives flour weight
Add water to half the starter weight (again, 50% of starter)
Divide water weight by flour weight to get hydration.
Then as long as the hydration is the same the quantity can be whatever you want. Correct?
Thanks for checking my math! (I failed college algebra 3 times, so I'm a little hesitant of my skillz :)