The owed 4-question independent S4 check ran (3/4 unaided, 0 blanks) after a 3/3 no-notes starter, then the session stopped at her request ("sorry but times up") about 22 minutes in, before the estimated-mean working was written and before the interleaved S4/P8/R7-R8 practice set. Starter, all non-calculator, 0 blanks: A17 4(x−2) = 3x+5 labelled "method marks only" → 4x−8 = 3x+5, 4x = 3x+13, x = 13 with the working written first, unprompted; A4 3(2x−5) − 4(x−3) → 6x−15−4x+12 → 2x−3, all four terms written, fifth clean minus-bracket expansion; G14-G16 triangle base 12 cm height 7 cm → 12×7 = 84, 84÷2 = 42, correct, units omitted, formula not stated — the first time triangle area has actually been tested, and it is fine. S4 check (calculator, no step or range prompts): Q1 mean of 14, 9, 21, 17, 9, 12, 16 → 14 ✓ answer only; Q2 mean from a books frequency table (25 students) → 1.6 ✓ answer only; Q3 estimated mean from a fresh 4-group puzzle-times table (5, 8, 12, 5; total 30) → "15 < t ≤ 25.6666667" ✗ — she multiplied each UPPER bound by its frequency (10×5 + 20×8 + 30×12 + 40×5 = 770, 770÷30) and, by inference, the lower bounds for the 15, presenting an interval rather than a midpoint estimate; when asked what one value would stand in for the 20–30 group she jumped straight to 20.6667, the correct answer (620÷30), but the midpoint working was never written down; Q4 median group → 20 < t ≤ 30 ✓ unaided. S4 stays developing: three of four independent but the estimated mean was wrong first time and its correct working is unrecorded.
FIRST: one fresh grouped estimated-mean question (4 groups), fully independent, with the midpoint × frequency line WRITTEN — today's Q3 used upper bounds (770/30 = 25.67) and the correct 20.67 was only spoken after questioning. Then the interleaved practice set (S4 mixed with P8 and R7-R8), now owed since 15 Sep, then a 4-question exit. Starter, no notes: one A17 equation NOT labelled method-marks-only (does working still come first?), one N15 error interval, one P4-P5 small-sample reasoning question. Do not prompt the range; do not ask for a "fair single value" before she has committed a method on paper.
Estimated-mean working never written (20.67 reached only after questioning); interleaved S4/P8/R7-R8 practice set and exit ticket not run — stopped at "times up" ~22 min in. Next session: fresh grouped estimated mean with full written working, then the practice set.
| Topic | Name | Change | Evidence recorded |
|---|---|---|---|
| A17 | Exam-ready → Exam-ready | 18 Sep starter, non-calc, labelled method marks only: 4(x−2) = 3x+5 → 4x−8 = 3x+5, 4x = 3x+13, x = 13. Three lines of working written before the answer, unprompted. | |
| A4 | Secure → Secure | 18 Sep starter, non-calc, timed: 3(2x−5) − 4(x−3) → 6x−15−4x+12 → 2x−3, all four terms written, −4×−3 = +12 correct. Fifth clean minus-bracket expansion (7, 9, 12, 15, 18 Sep), this one under a visible 10-minute timer. | |
| G14-G16 | Developing → Developing | 18 Sep starter, non-calc: triangle base 12 cm, height 7 cm → 12×7 = 84, 84÷2 = 42. Correct, unaided, first time a bare triangle-area question has actually been asked. Units omitted; formula not written out. | |
| S4 | Developing → Developing | 18 Sep independent 4-question check, calculator, 0 blanks: mean of a list 14 ✓ (answer only), mean from frequency table 1.6 ✓ (answer only), median group 20 < t ≤ 30 ✓. Estimated mean ✗ first time: used upper bounds ×frequency (770/30 = 25.67) and gave an interval 15 < t ≤ 25.67; produced the correct 20.67 immediately once asked what value stands in for a group, but never wrote the midpoint working. |