J.N.
You can also supplement it, without having to tutor. Apply math to real-world situations. For example, when you're going to something that charges, tell him "it costs $__ for each person and there are __ of us. How much money will we need?" (multiplication). There are opportunities to practice adding, subtracting, multiplication, division, fractions, geometry, patterns, basically every elementary school math concept, all around us. We use math every single day. Just include him in your calculating.
I'm not saying to replace tutoring. It might be a good idea. But adding to that with real-world usage (don't even tell him he's doing math!) will also help.