Two overlapping kits: count required parts only once
By Erik Nilsen · Kroni2 min read
If your child needs particular parts, two cheap kits may contain the same parts repeatedly. Count which distinct parts are actually missing rather than only how many pieces the packs supply. Make a small contents list before comparing totals.
Label the parts with four letters
In a hypothetical example, your child needs parts A, B, C and D for an optional paper construction. Kit 1 contains A, B and C and costs 8 units. Kit 2 contains B, C and D and costs 7. A separate A costs 5 and a separate D costs 4. The arbitrary prices and contents are invented.
Both kits cost 8 + 7 = 15 units. They provide six pieces but only four distinct required parts. B and C appear twice. Those extras do not fill another missing requirement.
Kit 1 plus a separate D supplies all four for 8 + 4 = 12. Kit 2 plus a separate A also supplies all four for 7 + 5 = 12. Among these three listed choices, either kit-and-part option costs 3 less than buying both kits.
Check contents before count
A practical snag is choosing kit 2 at 7 as “cheapest” without including A. It is cheapest alone but not a complete solution. Ask your child to point to every required part in their selected combination.
If your child already owns A, the requirement becomes B, C and D, and kit 2 alone may fit. Do not buy another A merely because an earlier calculation included it.
This comparison assumes parts bearing the same letter are genuinely interchangeable. Check size or model for an actual purchase; an identical name does not always mean compatibility.
Ask your family: “Do we receive every missing part, and which parts are we paying for more than once?”
Carry the calculation into your family agreement
Kroni can keep track of your child's virtual balance. The app does not transfer money, so any actual purchase is paid for outside it. Agree on what you will record, then check the amount with your child afterwards. Do not deduct a possible cost as though the purchase had already happened. Read about allowance in Kroni.
