I thought I would never need math in my career (in fact, I hated statistics so much in grad school) and now I work with statistics almost exclusively, and even if I don't do much of the heavy lifting, understanding where it comes from and why is very helpful.
Sometimes things just have a way of shaking out that you need this stuff. I was a foreign language major to avoid math. Now I'm here.
For Algebra, the puzzle piece of it is great if he likes puzzles. Also, game designers use math A LOT, and A LOT of algebra  so if he likes video games, that might be a way to relate. People who write computer programs use all sorts of math, including algebra.
Something as simple as figuring out what you need to tip (total times .2 equals x) is a good example of algebra. Plus you need algebra to understand the equations for geometry, which he might like better.
Also, baking! How do you double or halve a recipe?
