Sumdog's engaging multiplayer games encourage students to practice their mathematics, reading and writing.

As they work, our adaptive learning engine monitors their progress, and targets questions to their needs. These questions are drawn from hundreds of fine-grained skills, aligned to the Common Core.

Each game can be used to practise any skill, leaving students free to play what they want - while teachers and parents keep control over what they're learning.

And the best bit? Lots of Sumdog's games - and some powerful teacher tools - are completely free, with no time limit.