You can teach kids at any age almost anything and they do not bother if it is kind of interesting, but from what I have noted something that kids 2-5 year need

You can teach kids at any age almost anything and they do not bother if it is kind of interesting, but from what I have noted something that kids 2-5 year need half a day to learn, kids at 8-11 years need only 5 minutes or so. And they forget it if left at that, at the same pace. The key point is to choose the right moment when kids have interest and can learn it relatively fast, and make sure to repeat it somehow in non-boring ways. And all that I get usually wrong.