my comments.
If you have lived in the midwest, you will have to re-consider that "your child is good at maths". Being good at maths in other places is quite different from NY or CA. I know multiple examples that the kids in our state (not midwest, an even more lagged state) were leaders in math teams and get state maths prizes in mid-school. After transferring to CA or NY city, they suddently drop from top tier to mid-tier. Kids felt really difficult to accept the facts and had struggled. Most of them gave up maths; not necessarily they were not good enough, but mostly because they had difficult time to understand the transition as kids. If their family stayed in our place, they would still likely be the top maths students. My suggestion is to wait a semester and see if your kid is ok with his current speed.
Of course if your kid is truly good at maths, it will be different.