X01 · Optional projects job
Six display packs each hold seven cards. Two cards from each pack need replacing, plus three spare cards. How many replacement cards should be prepared?
Use scrap paper or a private explanation. No purchase, household information or public performance.
Adult teaching after an own try
Answer
6 × 2 + 3 = 15 replacement cards; 42 is the original packed total, not the replacement request.
Why
Discriminate relevant quantities rather than multiply every number.