Yes, but they should be taught it in a way that is appropriate to their age and ability to learn. A high school student’s math course is going to a completely different than an elementary school students math course. Not just in content, but in approach, type of lessons, length of lessons, reinforcement work, etc. At the same time, elementary school students need a lot more unstructured time. We might think of this as play time, but it is certainly learning. Learning social skills, learning how to get along with others, and learning how to solve problems in the real world, learning, how to address conflict, etc.