Nigeria is 82 times larger than Gambia.
Area: 11,295 km2 World Factbook
Population: 1,925,527 (July 2014) World Factbook
The Gambia is a country in West Africa. It is surrounded by Senegal, apart from a short strip of Atlantic coastline at its western end. It is the smallest country on mainland Africa. Wikipedia
Area: 923,768 km2 World Factbook
Population: 177,155,754 (July 2014) World Factbook
Nigeria, officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. Wikipedia