Our solar system formed around 4.6 billion years ago. It is made up of the sun and the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto has now been designated a dwarf planet. The solar system is vast, it took the Voyager 2 twelve years to reach Neptune.
See if you can solve these four more 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.