taxable income:4000+100=4100
SIN:就这个case来说,和上面一样。如果你有work related deductions and cost of deriving income,就把它们从gross income(assessable and exempt income)里面减去
SNI的意思不是gross income 减去你已经交的税,而是你的gross income(assessable +exempt income)减去你的work related deductions and cost of deriving income(even if they are not allowable as tax deductions)
在这里值得注意的是,SNI 还包括你的income that is exempt from tax,比如Army reserve pay之类的