Mathematics case study
From Diagnostic Evidence to Targeted Teaching
Year 6 Mathematics · Formative assessment
A Te Mātaiaho-aligned Year 6 sequence combining explicit place-value teaching, visual representations, diagnostic evidence, needs-based grouping, and planned extension.
THE TEACHING QUESTION
How can I identify which parts of decimal place value need another representation, explanation, or extension?
EVIDENCE I USED
I used a six-item diagnostic, place-value representations, a hinge question, verbal and written strategy explanations, practice responses, exit tickets, and short application tasks.
TEACHING DECISION
The evidence informed needs-based grouping, visual place-value models, targeted prompts, independent practice, and extension. I planned the next lesson around the specific criterion that was not yet secure rather than giving everyone more of the same practice.
CONCEPT-LEVEL RESPONSE
The status flow was class-wide. The teaching response was concept-specific.
Each check was read through a mathematical lens so that support and extension could target the idea beneath the answer.
| Concept | Diagnostic lens | Teaching response | Follow-up evidence |
|---|---|---|---|
| Decimal representation | Match models, fractions, and decimals; explain the value represented. | Reconnect grids, fraction language, decimal notation, and place-value charts in guided matching tasks. | A matched representation and an explanation of what remains equal. |
| Tenths, hundredths, and zero | Distinguish 0.4 from 0.04 and explain zero as a placeholder. | Rebuild the values on a 10 × 10 grid, name the unit aloud, and locate every digit on the chart. | An exit response comparing 0.3 and 0.03, including the role of zero. |
| Scaling by 10 and 100 | Separate the answer, estimate, model, and explanation; use 1.2 ÷ 100 as a hinge question. | Use fixed decimal-point place-value charts and digit cards, then target chart practice where fewer than four checks are secure. | Accurate ×/÷ calculations supported by a reasonable estimate and place-value explanation. |
| Inverse reasoning and application | Check operation choice, inverse reasoning, units, and whether an answer is reasonable. | Use work-backwards problems and measurement contexts; reteach, practise, or extend from the five-criterion profile. | A short context solved, labelled, explained, and checked with the inverse operation. |
Evidence boundary The concept-level criteria and teaching responses come from the lesson sequence. The retained public data supports the daily class-status flow, but it does not contain a numeric before-and-after tally for each concept.
RECORDED PROGRESS
Assessment changed the next teaching move.
Aggregated status changes across three daily checks, shown alongside the targeted teaching response recorded in the sequence.
| Assessment point | Status totals | Teaching response |
|---|---|---|
| Mon 17 Aug27 assessed | Emerging: 13 · Developing: 2 · Proficient: 8 · Extending: 4 | Six-item diagnostic; represent tenths and hundredths; use a place-value chart; identify support and extension needs. |
| Tue 18 Aug27 assessed | Emerging: 8 · Developing: 0 · Proficient: 16 · Extending: 3 | Retrieve from the previous check; use place-value charts and digit cards for ×/÷10 and 100; provide targeted practice or extension. |
| Wed 19 Aug27 assessed | Emerging: 3 · Developing: 0 · Proficient: 20 · Extending: 4 | Use the 1.2 ÷ 100 = 0.012 hinge question, inverse operations, and application; use the next check to plan reteaching or enrichment. |
Evidence boundary The flow shows aggregated status changes across daily checks. The current public dataset does not publish individual answers or map each question-level error to one learner’s pathway.
WHAT HAPPENED NEXT
Across the three recorded checks, status classifications changed alongside these targeted teaching responses: 5 Emerging and 2 Developing classifications moved to Proficient between Monday and Tuesday, and a further 5 Emerging classifications moved to Proficient between Tuesday and Wednesday. These are aggregated status changes, not individual answer records or a causal claim.
REFLECTION & NEXT STEP
The flow makes the progress visible while keeping the claim bounded: the next step is to connect future item-level evidence to the same responsive grouping process without publishing identifiable records.
RELEVANT PROFESSIONAL PRACTICE