The Roots of the Equation

I took some photos today at the AMNH with their scales with the intention of posting them as Estimation180-type challenges. I realize as I review the photos, though, that there were some issues. The numbers fluctuated a lot when I stood on the scales, so the pictures I have vary by a huge margin (+/- 30 pounds to my Earth-weight). They didn’t fluctuate when I put my bag on, but not every scale register its existence.

Estimation #1 – Here’s my bag (laptop, iPad, book, charger, 3DS). How much does it way?

(Answer: 21 pounds.)

Then the next estimations – how much would my bag weigh on Saturn? How about on the surface of a Red Giant Star?