The textbooks there are biased towards the mainland, and the mathematics in primary schools is the same as that in the mainland (I don't know about middle schools because I am only a primary school student). English there is the easiest for other schools in Macao, but it is difficult for the mainland. You don't have to be afraid, because Chinese is simpler than the mainland, and if you transfer from the mainland, your written and spoken Mandarin (final exam) will definitely be the first in your class.