A fun and practical way to incorporate math into your child’s love of Lego.
Take a look at Lego catalog prices, then go to FB Marketplace, a physical/online reseller, and/or craigslist for the same sets.
The basic math is about 10 cents per piece for a new, non-franchise set (City, Friends, etc.) Sets with special minifigs (Batman, Minions, Toy Story) go above that.
With that knowledge, it becomes much easier to price compare without looking up the new set price.
This could be a practical way to discuss value and price comparisons in a field of interest. I know my boys can look at a price and say, “That’s ridiculous.” Makes them much more helpful in deciding when and where we spend our Lego budget.