Guessing figures will be sketchy (how either Israel/Palestine will know straight away how many people have died when explosions happen in their territories I do not know).
And I'm not making excuses for Hamas - far from it. Just on a rational sense, 80 beds doesn't equate to = 500 people. But it wouldn't surprise me if the number could be high given the population density in small areas. Hospitals are bound to be overflowing with injured, wounded, family members, friends etc. Not to mention surrounding areas given the close proximity of other buildings.
It's hard to trust either side on any matter with any release of info that comes out. Israel prevented food/water/electricity/fuel supplies coming into civilians for quite a long time, and Hamas are terrorists with an extreme agenda to kill anything in its path.
Both claim their own 'we'll do right by our people' agenda. Without realising innocent lives are lost on both sides.