HowlerKarma said it so much better than I did and without typos. If you have difficulty with a mentor, there are some online explanations (Khan, BrainPop, etc.) and online practice- ixl.
We're going to hit the end of my "teaching skills" as soon as algebra comes along. At this rate, it could theoretically happen at age nine or even age eight. My plan is to hand it over to DS's excellent private school teachers and/or find enrichment/tutoring through a center or individual if necessary.
Seriously, cannot overstate the importance of numeracy and competence with calculation. Find some challenging word problems (I've said this on several threads, but Singapore word problems hit the sweet spot for DS's abilities). Beast Academy is challenging- we do it to enhance analytical and emotional (did I mention not easy to solve?) skills.
