Maybe you do things differently round here, but I'd rather expect to find takeoff weight ... present in both the takeoff and landing calcs?
For a 152 I would expect to use max weight, with no allowance if I took off a bit lighter. Obviously for airliners the actual weight is taken into account.
At what size aircraft does the actual weight start to get used (routinely, not just by people who are trying to shave a couple of metres off their requirement)?