← GCSE Mathematics

A9-A10 Linear graphs, y = mx + c, gradient

Currently Developing · last touched 2026-10-10

Homework #8 (6 items on paper, due Sun 11 Oct) is out: do not re-set its items; mark it from the photographs with tracker_exam_mark_test, then one maths session with the review. Until that marked attempt is on this trail it is still owed. Looking for: every working line written, the gradient sum first, no swap of gradient and start value, a check line. Plotting from a table, reading a real graph and perpendicular lines untaught.

Every change

WhenChangeEvidenceSession
2026-10-10Developing → Developinghomework #8 "Straight lines: weekend homework" loaded onto the tracker 10 Oct (set 9 Oct, due 11 Oct): 6 questions, 15 marks, on paper, at /exam/8 — substitution, gradient and start value from two points, scaffold withdrawn by Q5, rearranging 2y = 8x + 6.standalone
2026-10-09Developing → DevelopingHomework set by parent on 9 Oct for the weekend of 10-11 Oct: 6-item handwritten sheet, non-calc, unaided, 15 marks (table of values; equation from start value and step; two points with x = 0; two points neither at x = 0 with the lines stated; the same in bare exam wording; gradient and start value from 2y = 8x + 6). Set, not yet answered. To be photographed and marked in the parent project. No status change.standalone
2026-10-09Developing → Developing9 Oct, cold, non-calc: line through (2, 5) and (6, 13), question worded 'work out the gradient, then substitute a point to find the start value': y = 2x + 1 first time in under 1 min, 1/1 unaided. No working written (replied 'in my head' when asked for a photo before marking). Same item as the 7 Oct paper (y = 2x + 2.5 then). Neither point at x = 0. Session 90. Retrieval outcome: correct.standalone
2026-10-08Developing → Developing8 Oct opener, cold, non-calc: line through (0, 2) and (4, 14), asked for gradient, equation and a check with x = 4. Wrote y = 3x + 2 first time with the check 4*3 + 2 = 14. Gradient working not written. 1/1 unaided; one point at x = 0.session 88
2026-10-07Developing → DevelopingExam practice 7 Oct (test #7, attempt #15, timed) Q8: line through (2, 5) and (6, 13), she wrote 'y = 2x + 2.5', no working; 1/3. Gradient right and placed as the multiplier of x; intercept not found by substituting a point. Marking only: no status change. Retrieval outcome: incorrect.standalone
2026-10-06Secure → Developing6 Oct, non-calc, after 2 misses in the morning warm-up. Gradient from two points 2/2 unaided with lines ('4, 8/2'; '11 - 5 = 6, 6/3 = 2'). Equation from gradient and start value 0/2 first time: 'i don't know' on (0,3),(2,11); 'y = 5x + 2' for gradient 2, start 5, then 52 and 17 computed from it. Right only after counting along the line ('y = 4x + 3'; y = 2x + 5 chosen from two). One fresh unaided item in 'start at 1, add 6 for every x' wording: 'y = 6*x +1'. Last check 2 Sep.session 77
2026-09-03Secure → Secure2 Sep starter: gradient 3 and y-intercept −4 read correctly from 2y = 6x − 8, though the rearranged line y = 3x − 4 was not written down first.session 2

In papers

AttemptPaperQMarksNote
Exam practice — week 41 — GCSE Mathematics sectionexam-skills #781/3M1: gradient 2 implied by 'y = 2x + …' (no working shown; benefit of the doubt). M0: no substitution of a point seen. A0: c given as 2.5 (possibly 5 ÷ 2 from the first point); y = 2x + 1 required. No working on a 3-mark question; 1 min on focus.

Materials

Corbettmaths: Drawing Graphs using xy Tables Video
Completing a table then plotting. Untaught sub-skill: plotting from a table. Watch before teaching.
video
Corbettmaths: Drawing Linear Graphs worksheet
Plot y=mx+c from given x-values.
practice
Corbettmaths: Real Life Graphs Video
Untaught sub-skill: reading a real-life linear graph.
video
Corbettmaths: Real Life Linear Graphs Practice Questions
Worksheet (Video 171a) for interpreting real-life linear graphs.
practice
Corbettmaths: Perpendicular Lines Video
Untaught sub-skill: perpendicular lines. Negative-reciprocal gradient method.
video
Corbettmaths: Parallel and Perpendicular Lines worksheet
Finding the perpendicular line through a point (Videos 196/197).
practice