Examples include Khan Academy, Prodigy, and Math Playground. Interactive and Gamified Learning: Platforms like DragonBox and Cool Math Games provide interactive lessons and challenges to make learning math concepts engaging. Introduction of 15-puzzle The 15-puzzle, also known as the fifteen puzzle, ...
For example, the task "Design a playground for the school" is open since the correctness depends on an ill-defined interpretation and one has to consider validness instead. They usually involve a certain amount of creativity and may be related to investigation tasks. In the context of Math ...