147 and Daneil Rosen, I think you are both wrong but DR is closer to being right.
All people must give tzidaka (charity), however masser (10%) is not an obligation but good hanhaga (maybe a minhag). if you are being supported i.e. taking tzidaka to live, then it is worth talking to a rabbi, because there are strong grounds not to give masser as well as other halachos related to money, such as shopping in a Jewish store even if it is more expensive.