Scanning more photos

Last week I picked up two bins of photos and photo-negatives from my parents. Last night I started scanning. My intention is to only scan negatives (or occasional one of a kind positives such as Polaroids) and put the bulk of this material aside. I will re-assess that plan once I get to the bottom of the stack. My estimate is that there are perhaps 90 rolls of film. What I won't know until later is if there are any large gaps which would imply that there would be another cache of these negatives stored separately.