My calculation is nbv b/f is (75K-15K) 60k -1.5k(half year depreciation) then i get 58.5k nbv and revaluation to 66.3k .so my revaluation surplus is 7.8k. For another 6 months depreciation I’m use method time apportionment (20 x 12 mth-6 mth) =234 month .That means my another half year dep amt is 1.7k (66.3/234 mths x 6month)