We designed LightUp for kids in the upper elementary and middle school grades. That said, a lot also depends on a kid's background. We've had younger kids build simple circuits with LightUp on their own, and older kids enjoy using Arduino with our programmable blocks. The exact age labeling will depend on safety standards.
The Maker Camp Kit is similar in composition to the Maker Deluxe Kit and supports the same projects, but has many more blocks. We haven't nailed down the exact number, but imagine enough to support 5 kids working on their own, or 10 kids working in pairs.