Asia dwarfs Nigeria: about 44,580,000 km² km² against 911,496 km² km². At true size Asia is about 48.9× larger — the whole of Nigeria fits into Asia roughly 48 times.
The old Mercator map treated both about equally (1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Nigeria fits 48× into Asia.