We have done math learning centers for our boy but still trying to find a mentor for him. What we are looking for is not so much a tutor but someone who knows their math and explains what a mathematician does and how a mathematician thinks. How a arithmetician looks at the owrld and how they put what they see on paper.

IMHO the relationship should be like an apprenticeship

DS9 - Starting 9th grade
DS7 - Starting 5th grade