Two missing roles

Complete neutral source

Two separate fictional records use cards. Record 1:□−175=428, where 175 cards are used and 428 remain. Record 2: 620−185=□+240. Keep the records separate. There is no supplied history of a learner’s earlier work.

Eligibility

After unknown start and two-sided equality have both been taught, e.g. Days 57–58. One record or one prompt may be enough; do not require all four for a useful observation.

Access and help

Read or sign the exact source and prompts neutrally, enlarge them, or scribe the learner’s chosen words. A figure, operation, regrouping, equation role or check supplied by an adult is mathematical help and is recorded as such. Show, draw, type, sign or use usual communication. One component can be enough; pause/pass/finish are choices. Four own spaces are genuinely empty. Models, criteria and next lessons stay on separate staff pages.

First later limit

First/later are opportunity labels, not fixed order, matches, calibrated difficulty or learning gain. If source/answer exposed, record that rather than claim unseen.

Prompts

1. For Record 1, say what the box counts and find it.

2. Substitute your Record 1 value into its original equation and check.

3. For Record 2, find the box value. Show what the complete known side is first.

4. Check both full sides of Record 2 after substitution.