← Lessons
Lesson overview

BUILD · Science · Week 10A · Explore

Rock Hardness: Mark or Groove?

Sequence outcome: Rocks: test hardness.

🎯 Learning objective: I can explain relative hardness and identify a fair, safe scratch method for comparing rock samples.
✅ Success criteria
  • I can say that hardness means resistance to scratching.
  • I can distinguish a loose tool streak from a groove that remains after wiping.
  • I can change the sample while keeping the tool, passes and guide as consistent as practical.
Arrival · retrieve last lessonStarter · create the need to knowI Do · picture firstWe Do · everyone commitsI Do 2 · connect the second ideaWe Do 2 · interactive labIndependent · evidence of learningExit · adult Audience closes BUILD
🧪 Scratch Evidence Lab: wipe the mark, check the groove and keep the method the same.⏱ 40 minutes🔁 Live Lundy loop↺ Retry without penalty
✏️MARK · A LINE APPEARSAFTER THE TOOL PASS.do not decide yet🧽WIPE · REMOVE LOOSETOOL MATERIAL AND DUST.check safely🔎GROOVE · RECORD WHETHERAN INDENTATION REMAINS.relative hardness
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 4 min
🚪 Arrival · retrieve last lesson
Retrieve only what has already been taught
  1. W9B: a useful comparison kept one criterion unchanged for every specimen.
  2. W9A: visible properties helped us group rocks but did not reveal every tested property.
  3. W8A: a fair comparison matched the number, unit and basis.
  4. Lead-in: a scratch test needs a stated method before its marks become evidence.
New to this class, absent, or not sure? Everything needed is in the retrieval box above. Read it, point to it or ask a familiar adult to read it exactly.
◆ Supported
  1. Point to the fixed criterion used in W9B.
  2. Choose the observation: visible crystals or ‘this must be granite’.
  3. Point to the same-basis label rule from W8A.
  4. Lead-in: choose the image with a groove that remains after wiping.
▲ Standard
  1. Explain why the Lessons 3–4 sorting question stayed unchanged.
  2. Name one visible rock property and one property that needs a test.
  3. State why matching units makes a comparison fair.
  4. Lead-in: what must be checked before a pale line is called a scratch?
★ Stretch
  1. Distinguish classification under a rule from a test of material behaviour.
  2. Explain why specimens with the same rock name may still vary.
  3. Name three controls for a relative scratch comparison.
  4. Lead-in: explain why hardness is not the same as mass or resistance to breaking.
Equivalent response routes
☝ point / choose🗣 say / sign🧩 demonstrate⌨ type / exact scribe↺ re-attempt
🔊 Read-aloud route: a familiar adult may read the task exactly while the text remains visible. No device voice or media permission is required.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 4 min
🌱 Starter · create the need to know

A pale line appears after a secured blunt tool passes over a rock. What should happen before we call it a scratch groove?

LOCAL VISUAL HOOK · FRAME 1
PASS 1 · a pale line appears
PASS 1 · a pale line appears
Do not decide yet. A pale line can be tool dust sitting on top.
LOCAL VISUAL HOOK · FRAME 2
WIPE · remove the loose dust
WIPE · loose tool dust removed
Wipe, then look again. Only a mark that survives the wipe counts.
LOCAL VISUAL HOOK · FRAME 3
OBSERVE · groove, or gone?
groove REMAINS · softerline GONE · harder
A groove that stays = the rock was scratched = softer than the tool. Line gone = harder.

Commit one first idea. Predictions are held, not marked. Pointing, selecting, saying or signing all count.

🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 5 min
👩‍🏫 I Do · picture first

Make the first scientific idea visible

HARDNESSresistance to a scratchhow well a material resists being scratched under a stated method
GROOVEa line cut into the surfacean indentation that remains in the sample after loose material is wiped away
CONTROLwhat we keep the samea relevant condition held as consistent as practical so samples can be compared

WHAT THIS MODEL HELPS US SEE

The mark–wipe–groove sequence makes the deciding observation visible and keeps loose tool streaks separate from damage to the sample.

WHAT THIS MODEL DOES NOT SHOW

This is a relative classroom comparison with one tool and method. It does not give a Mohs number, prove construction strength or represent every specimen of a named rock.

Step 1

Place a teacher-pretested dry sample in a stable tray. Use only the secured blunt scratch jig or a teacher demonstration.

Step 2

Use the same tool, guide length, number of passes and safe force proxy. Never press harder to make an expected result appear.

Step 3

Wipe the line with the prepared method, then inspect from the same viewing position for a remaining groove.

Word help keeps the scientific term visible and adds a plain-language bridge.

✏️ Scratch tester · mark, wipe, look

Same tool, same guide, same number of passes. Only the rock changes. Press the steps in order.

ready
Pick a code, then press 1, 2, 3.
Hardness = resistance to scratching. It is NOT weight and NOT "hard to break". Loose dust is not a scratch.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 5 min
🤝 We Do · everyone commits

The pale line wipes away and no indentation remains. Which record is accurate?

Everyone commits before explanation.

Use a button, point, say/sign or let an adult operate the chosen button. A retry is information, not a penalty.

🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 4 min
👩‍🏫 I Do 2 · connect the second idea

Connect the model to the second idea

Connection: the model is useful when its visible pattern is translated into a scientific explanation.
Connection 1

Compare outcomes with cautious words: deep groove, shallow groove, faint groove or no groove under this method.

Connection 2

A clearer remaining groove means lower resistance to this particular scratch method; it does not measure every kind of strength.

Connection 3

If a sample flakes, crumbles or makes dust, stop. Preserve the observation and use the representative digital or image route rather than forcing a repeat.

MODEL STRENGTH

The mark–wipe–groove sequence makes the deciding observation visible and keeps loose tool streaks separate from damage to the sample.

MODEL LIMIT

This is a relative classroom comparison with one tool and method. It does not give a Mohs number, prove construction strength or represent every specimen of a named rock.

🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 4 min
🤝 We Do 2 · interactive lab

Mark, Wipe or Groove Evidence Gate

Place each method or observation under the role it performs in a valid hardness comparison.

Lock the stated method.Commit a prediction.Make or reveal the safe tool pass.Wipe and inspect.Record the bounded result.

Cards to place

Matching groups

The evidence gate begins with a locked safe method. No pupil handles an unsecured tool.

🧩 Science glitch · find and repair it

Claim: Hardness glitch: the heaviest rock is the hardest and cannot break.

🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 10 min
✏️ Independent · evidence of learning

Plan and direct a safe two-sample relative hardness comparison, then record the method, groove observation and bounded conclusion.

👐 Physical route

Two teacher-pretested coded dry rock samples; stable trays; secured blunt scratch jig or teacher demonstration; fixed guide; wipes; hand lens; result card; eye protection where required by local assessment.

Same outcome: I can explain relative hardness and identify a fair, safe scratch method for comparing rock samples.

🖥 Offline digital / director route

Use the in-page evidence gate and supplied representative mark/wipe/groove observations. Label them as model data, not results from the class samples.

Same evidence: A Rock Hardness Method Card with prediction, changed sample, controls, after-wipe observation and a relative conclusion within the stated method.

🧰 Equipment / setupTwo teacher-pretested coded dry rock samples; stable trays; secured blunt scratch jig or teacher demonstration; fixed guide; wipes; hand lens; result card; eye protection where required by local assessment.
🛡 Safety / sensoryFollow the school's current rock-testing risk assessment. No unknown, sharp, dusty or crumbling samples; no hammering, breaking, tasting, smelling or dust blowing. An adult controls the secured tool. Stop immediately on flaking or dust and wash hands.
🖥 Offline parityUse the in-page evidence gate and supplied representative mark/wipe/groove observations. Label them as model data, not results from the class samples.
No-equipment/access route: Direct the adult tester, use macro before/after cards or interpret the fixed data. Handling the rock or tool is never required.

◆ Supported

Choose groove/no-groove after-wipe cards for two samples and direct the adult through the same method.

Scaffold

Use pictures for tool, passes, wipe and groove. Complete: After wiping, __ remained.

▲ Standard

Compare two coded samples with the same stated method and justify which resisted a groove more.

Scaffold

Use: We changed __. We kept __. Sample __ showed __, so under this method __.

★ Stretch

Evaluate the controls, distinguish hardness from strength and propose one safe repeat or method improvement.

Scaffold

Preserve the first result and explain why the improvement would make the comparison more dependable.

Evidence gate

1 · Pupil decisionPrediction, question, method or choice is visible.
2 · Observable evidenceA result, source note, model state or adult observation is preserved.
3 · Pupil meaningA Rock Hardness Method Card with prediction, changed sample, controls, after-wipe observation and a relative conclusion within the stated method.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

⏱ 4 min
🎫 Exit · adult Audience closes BUILD

Finish with evidence and a genuine adult Audience

Supported

Complete: hardness means resistance to __. After wiping I saw __.

Standard

Explain how the method distinguishes a tool streak from a groove and name two controls.

Stretch

Give a bounded relative-hardness conclusion and explain one thing the test cannot show.

Adult Audience

The familiar adult genuinely receives the pupil response, then says back the Science they heard or saw. The adult does not add a score or rewrite the pupil.

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

Session state is temporary. Reload clears responses; there is no account, upload or saved pupil identity.

⌂ Start
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

Staff route

TA Brief · Lesson overview

Priority

Settle, wait and protect the learning goal.

Least-prompt move

Use the least prompt needed, then fade it.

Prompt ladder

WAITSELF-PROMPTVISUAL CUEGENERAL VERBALSPECIFIC VERBALMODELDIRECT SUPPORT
Read-aloud availability: a familiar adult can read the exact current task while the text remains visible. Device speech is intentionally omitted so the deck asks for no media permission and stays dependable offline.

Guidance and access

Live Lundy loop

🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE

SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting

Audience is real only when a familiar adult receives the response. Influence is real only when one next teaching move visibly changes.