Have you been teaching him at home? No, it isn’t normal and it’s not going to do him any favours going forward.
What he needs is depth and building up other areas where he may be weaker…and bike riding and swimming and camping and play dates with friends.
Mine is in Y3 and is very confident at maths. So we focus on reading. If I taught him how to solve equations, yes, he could easily do it. But I haven’t. Because I’d rather he spend his time out of school playing in mud and in the river with the dog.
When they move to secondary school, unless you go very specialist independent, there will be limited stretch beyond top sets because there will be 1000-2000 students. They could all benefit from one to one teaching, but it’s not there. My dd is top sets math and science. The curriculum is the curriculum. It builds the base for GCSEs or whatever your equivalent is. Yes, even when they’re put in for the more academic GCSEs, triple science, etc. You have to prepare for the papers you’re given, not for what you wish him to be doing.
Depth in what he’s good at, focus on his weaknesses, whether reading, writing, art, swimming, sports, social skills, etc.