Africa dwarfs Madagascar: about 30,370,000 km² km² against 594,622 km² km². At true size Africa is about 51.1× larger — the whole of Madagascar fits into Africa roughly 51 times.
The old Mercator map treated both about equally (1× vs 1.1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Madagascar fits 51× into Africa.