Solve more real-world problems WITH the skills he already knows.
Building things, measuring things, scaling problems (kitchen math, consumer math, etc) and working with time and money. That kind of everyday math, basically.
Practicing
pointless or single-step calculations is a non-starter and honestly, he doesn't need to. He knows what he's doing. He just needs to practice using the tools he already has, so that he can recognize how to tear apart a complicated problem and use the tools he already has.
So let him help with some real-world stuff instead!
