X04 · Optional projects job
Four kits need 19 labels each. Explain two efficient strategies and show why both fit.
Use scrap paper or a private explanation. No purchase, household information or public performance.
Adult teaching after an own try
Answer
4 × (20 − 1) = 80 − 4 = 76; or double19=38,double38=76.
Why
Choose and connect efficient representations, not speed.