Oceans and Continents Arithmagons

There are seven continents on Earth covering about a third of the Earth's surface. Continents include Europe, Asia, North America, South America, Australia, Africa and Antarctica. Oceans cover two thirds of the Earth's surface. The five oceans are the Pacific, Indian, Atlantic, Arctic and Southern Ocean (sometimes called the Antarctic).

See if you can solve these four difficult arithmagons.

The aim of an arithmagon is to work out which numbers go in the empty circles. The numbers in the square boxes are made by adding together the numbers in the circles either side.