That felt easy because this is how Allah:subhanahu: has explained it to His people in Quran that Shaitaan whispers the thoughts into us. There are quranic references and prohphetic guidance to conclude that shaitaan only has power to suggest things not the power to make us do those things… Then, it gets a bit complicated for a child of that age so you let the child memorize Surah Falaq and Surah Naas first and then eventually explain the rest…