Venn Diagrams: Sums

GAME INFO
Venn diagrams to do sums online. Drag the numbers to the coloured areas, and observe the union of sets and intersection with the Venn diagrams. The numbers you place at the intersections of the Venn Diagrams will be summands for both sets. The aim is to get the numbers inside the coloured squares to add up to the requested number, bearing in mind that the number of the intersection participates in several sums, as many as the number of sets to which the intersection belongs.