Teacher copy: This page may include teaching prompts or answer keys. Answer keys in this public library can be viewed by anyone. Give learners a clean prompt, use checks as formative evidence, and change a case locally when prior access matters.
Target: independently transfer Z/A and isotope comparison to new Files R/S. The check and worked key are public, so it is formative only. Prepare: new case, neutral count mat, support log.
Launch · 2 min. State the task: derive counts, compare two records, and refuse one unsupported claim.
Source access · 4 min. Release Files R/S without the key; note read-aloud, scribing or other access support.
Independent plan · 5 min. Learner marks each given Z/A/status, identifies the subtraction, and notes one claim the files cannot prove.
Independent response · 7 min. Choose Day 5 route and capture a first response; do not supply worked counts during this window.
Self-audit · 4 min. Learner checks p+n=A, neutral e=p and same-Z isotope reasoning.
Submit · 3 min. Collect first response/support log; consult the public key for the next teaching move.