π§ Watch me think: The card represents bone, the pin represents the elbow and the strings represent muscle pulls. Compare the model with a simplified arm diagram.
muscle β a soft part of the body that pulls.
pair β two muscles that work together, taking turns.
π€ We Do Β· say it before I click
Which one is pulling?
Tap a card. Everybody decides. THEN I click. Point at the model, or your own arm if you choose β top or underneath?
π€ We Do Β· the same machine twice
Control and compare the two models
Do not tell me yet. Choose a move. Watch each connection. Point, sign or say what stayed attached.
Predict first: Which muscle pulls to bend? Can a muscle work while the arm stays still?
Muscle model
Card-and-string model
Choose a move after making a prediction.
What this model leaves out
Real muscles develop tension. They can shorten, stay the same length or lengthen while active. Our simple opposing pair explains deliberate bending and straightening; gravity and other muscles affect a real arm. A string does not contract by itself.
Two opposing muscles can pull the joint in different directions. Neither one of them can push.
Evidence loop β two muscles, two jobs, one sentence
When the arm bends,the biceps CONTRACTSand the triceps RELAXES.
Assessor witness Β· what the adult is watching for
Named biceps and triceps as a working pair.
Stated that muscles pull and never push.
Demonstrated contract / relax on a model.
πΈ Capture: Photograph the pupilβs model arm mid-bend with their label cards on it.
π€ We Do 2 Β· sort, then write
True or not true?
Sort, donβt guess. Put each card in the right bin.Sorted 0/5
Muscles pull
Muscles push
Muscles work in pairs
Bones move on their own
Biceps and triceps take turns
β TRUE
β NOT TRUE
βΈ STOP for today β label and keep your work. Wednesday P2 (10:10β10:50): use Resume period 2 on the title screen.
Use the remaining practice time: Use the final three minutes to direct two model movements. Each learner may place, point to or say the pulling label before the reveal, then correct one swap.
βοΈ Independent Work
Your turn β pick your tier
βΆ Wednesday P2 (10:10β10:50) β restart here. First recall the last lesson. This workshop has time to check and tidy up.
32-minute workshop. Follow the steps below. Choose a route with your adult. You can point, sign, draw or write. You can tell an adult what to do. Each way can show your science.
32:00
β Supported
Use a card arm made by an adult. You can ask the adult to move it for you. Bend it, then make it straight. Move the CONTRACTS and RELAXES labels. Show which part pulls each time.
β² Standard
Build the arm. Test a bend. Then make it straight. Use the biceps and triceps labels to say what happens. Check the diagram. Fix a label if you need to.
β Stretch
Build and test both moves. Say why it needs a pull on each side. The string stands for a muscle. What is one way the string is not like a real muscle?
Build, test and improve a model arm
4 min: Find Mondayβs two labels. Check that the elbow join can turn. Choose to make the model or tell an adult how to make it.
20 min: Build the card arm or tell an adult how to build it. Pull gently to bend it. Try the other string to make it straight. Move the CONTRACTS and RELAXES labels for each move. Check the model against the lesson diagram.
2 min: Pens down if you are writing; pause and check. Check the diagram. Is there a string to pull for each move? You can tell an adult how to move the model.
6 min: Fix one label or join. Show both moves again. If ready, note one way the model differs from a real arm. Clear the bench.
Access and equipment: Use two card strips, two loose strings and labels. An adult cuts the card, makes the holes and fits the split pin. Keep the pin fixed in place. Pull gently. Do not use stretched elastic. No one has to move or show their own arm.
Action
Biceps label
Triceps label
Bend at elbow
________________
________________
Straighten at elbow
________________
________________
One thing I changed or checked: ____________________
The model differs from a real arm because: ____________________ (optional explanation).
π Lundy Loop
Where what you say changes something
This is where your voice changes what happens next.
π‘ Space
Ask for a ready-made card arm if the joins are hard to make. You can tell an adult how to move it. We want to see the science in your labels.
π£ Voice
Point, sign or say what you notice. Ask a question or say what would help you join in. You may pass or speak to the adult in private.
π Audience
Tell the adult who teaches this lesson. You can ask a partner to help pass on your message.
β Influence
The adult says what can change now. Agree one change to try. If it cannot happen, the adult says why. Check if the change helped. Ask before work is shown or shared.
π« Exit Ticket
Before you go
β Supported
Fill the gap: muscles work in a ______.
pair
β² Standard
When the arm bends, what does the triceps do?
relaxes
β Stretch
Explain why a muscle that could push would not need a partner.
If it could push it could move the bone both ways by itself, so no second muscle would be needed.
Slide 1/10
π πΈβοΈ
Muscles Work in Pairs β banked!
BUILD Science Β· Week 4 β
β I can name the two muscles in the arm pair.β I can say what happens to each muscle when the arm bends.β I can show the pair working on a model.
OPTIONAL EVIDENCE CHECK
Check one piece of evidence
Show an adult or chosen partner, or quietly check your own work against todayβs success: I can name the two muscles in the arm pair. and I can say what happens to each muscle when the arm bends.. Keep or correct one thing using the evidence.
The planned two-minute check belongs inside the workshop. If this optional panel is opened manually, resume when ready and allow for the pause in the teaching plan.
Knowledge Organiser β Muscles Work in Pairs
BUILD Β· White Rose Science Year 3 Β· Week 4
Key word
What it means
muscle
A soft part of the body that pulls.
contract
The muscle develops tension. It can shorten and pull.
relax
The muscle develops less tension. Its partner can lengthen it.
pair
Two muscles that work together, taking turns.
joint
The place where two bones meet and can move.
Key facts
A muscle can only PULL. It can never push.
That is why muscles come in pairs β one pulls the bone one way, the other pulls it back.
Arm bends: biceps contracts, triceps relaxes.
Arm straightens: triceps contracts, biceps relaxes.
Bones do not move themselves. The muscle pulls the bone.
Success criteria
I can name the two muscles in the arm pair.
I can say what happens to each muscle when the arm bends.
I can show the pair working on a model.
Muscles Work in Pairs
Name: ____________________ Tier ringed by adult: β Supported β² Standard β Stretch Date:
Learning objective
I can explain that muscles work in pairs to move a bone.
Teaching plan: Monday P3 (11:00β11:40) β Title through We Do 2: 40 minutes. STOP after We Do 2, label and keep the work. Wednesday P2 (10:10β10:50) β restart at Independent Work: 32-minute workshop, 4-minute pupil feedback, 4-minute Exit Ticket. Total: 40 minutes on each day; 80 across the week. Timers guide the plan and never advance a pupil automatically.
Today at a Glance
Meet the pair
Make the model move
Explain the swap
Arrival task
Watch the model arm bend, or bend your own arm if you choose. Which side is pulling β top or underneath?
Watch the model arm bend, or bend your own arm if you choose. Name the muscle you think is pulling.
Watch the model bend and straighten, or use your own arm if you choose. Say, point to or write what changed.
We Do β Sort each card into the right group
Muscles pull → ______________________________
Muscles push → ______________________________
Muscles work in pairs → ______________________________
Bones move on their own → ______________________________
Biceps and triceps take turns → ______________________________
WAGOLL
When I bend my arm the biceps contracts and pulls the bone up. At the same time the triceps relaxes so it does not fight it.
Scaffolding β β Supported
Adult notes β access & sensory Bodies and food are personal. Teach every idea on the model, the diagram or the picture card β never on a pupil's own body, and never on what a pupil has eaten. If a pupil steps out, the diagram waits for them.
Sentence stems
Sentence shape for today: 'When the arm bends, the biceps CONTRACTS and the triceps RELAXES.' Two muscles, two jobs, one sentence.
Word bank
muscle, contract, relax, pair, joint
Scaffolding β β² Standard
Sentence stems
Sentence shape for today: 'When the arm bends, the biceps CONTRACTS and the triceps RELAXES.' Two muscles, two jobs, one sentence.
Word bank
muscle, contract, relax, pair, joint
Scaffolding β β Stretch
Sentence stems
Sentence shape for today: 'When the arm bends, the biceps CONTRACTS and the triceps RELAXES.' Two muscles, two jobs, one sentence.
Word bank
muscle, contract, relax, pair, joint
Independent Work β β Supported
Task: Use a card arm made by an adult. You can ask the adult to move it for you. Bend it, then make it straight. Move the CONTRACTS and RELAXES labels. Show which part pulls each time.
Build, test and improve a model arm
4 min: Find Mondayβs two labels. Check that the elbow join can turn. Choose to make the model or tell an adult how to make it.
20 min: Build the card arm or tell an adult how to build it. Pull gently to bend it. Try the other string to make it straight. Move the CONTRACTS and RELAXES labels for each move. Check the model against the lesson diagram.
2 min: Pens down if you are writing; pause and check. Check the diagram. Is there a string to pull for each move? You can tell an adult how to move the model.
6 min: Fix one label or join. Show both moves again. If ready, note one way the model differs from a real arm. Clear the bench.
Access and equipment: Use two card strips, two loose strings and labels. An adult cuts the card, makes the holes and fits the split pin. Keep the pin fixed in place. Pull gently. Do not use stretched elastic. No one has to move or show their own arm.
Action
Biceps label
Triceps label
Bend at elbow
________________
________________
Straighten at elbow
________________
________________
One thing I changed or checked: ____________________
The model differs from a real arm because: ____________________ (optional explanation).
Independent Work β β² Standard
Task: Build the arm. Test a bend. Then make it straight. Use the biceps and triceps labels to say what happens. Check the diagram. Fix a label if you need to.
Build, test and improve a model arm
4 min: Find Mondayβs two labels. Check that the elbow join can turn. Choose to make the model or tell an adult how to make it.
20 min: Build the card arm or tell an adult how to build it. Pull gently to bend it. Try the other string to make it straight. Move the CONTRACTS and RELAXES labels for each move. Check the model against the lesson diagram.
2 min: Pens down if you are writing; pause and check. Check the diagram. Is there a string to pull for each move? You can tell an adult how to move the model.
6 min: Fix one label or join. Show both moves again. If ready, note one way the model differs from a real arm. Clear the bench.
Access and equipment: Use two card strips, two loose strings and labels. An adult cuts the card, makes the holes and fits the split pin. Keep the pin fixed in place. Pull gently. Do not use stretched elastic. No one has to move or show their own arm.
Action
Biceps label
Triceps label
Bend at elbow
________________
________________
Straighten at elbow
________________
________________
One thing I changed or checked: ____________________
The model differs from a real arm because: ____________________ (optional explanation).
Independent Work β β Stretch
Task: Build and test both moves. Say why it needs a pull on each side. The string stands for a muscle. What is one way the string is not like a real muscle?
Build, test and improve a model arm
4 min: Find Mondayβs two labels. Check that the elbow join can turn. Choose to make the model or tell an adult how to make it.
20 min: Build the card arm or tell an adult how to build it. Pull gently to bend it. Try the other string to make it straight. Move the CONTRACTS and RELAXES labels for each move. Check the model against the lesson diagram.
2 min: Pens down if you are writing; pause and check. Check the diagram. Is there a string to pull for each move? You can tell an adult how to move the model.
6 min: Fix one label or join. Show both moves again. If ready, note one way the model differs from a real arm. Clear the bench.
Access and equipment: Use two card strips, two loose strings and labels. An adult cuts the card, makes the holes and fits the split pin. Keep the pin fixed in place. Pull gently. Do not use stretched elastic. No one has to move or show their own arm.
Action
Biceps label
Triceps label
Bend at elbow
________________
________________
Straighten at elbow
________________
________________
One thing I changed or checked: ____________________
The model differs from a real arm because: ____________________ (optional explanation).
Exit Ticket
When the arm bends, what does the triceps do?
Assessor Witness Statement
Pearson Entry Level Science 8939 (E1βE3); AQA UAS science units Records what was observed, and at which level of independence.
Pupil
____________________
Lesson
Muscles Work in Pairs β BUILD Science Β· Week 4
Date
____________________
Observed in this lesson
β Named biceps and triceps as a working pair.
β Stated that muscles pull and never push.
β Demonstrated contract / relax on a model.
Assessor comment
Ring the tier the pupil actually worked at
β Supported
β² Standard
β Stretch
Assessor name ______________ Role ____________ Signature ______________ Date ________
Lundy Loop
Space: Ask for a ready-made card arm if the joins are hard to make. You can tell an adult how to move it. We want to see the science in your labels.
Voice: Point, sign or say what you notice. Ask a question or say what would help you join in. You may pass or speak to the adult in private.
Audience: Tell the adult who teaches this lesson. You can ask a partner to help pass on your message.
Influence: The adult says what can change now. Agree one change to try. If it cannot happen, the adult says why. Check if the change helped. Ask before work is shown or shared.
What I said:
What changed because of it:
Muscles Work in Pairs β Feedback Sheet
Keep with your portfolio.
Pupil name:
Date:
WWW (What Went Well):
EBI (Even Better If):
Level worked at: Supported / Standard / Stretch
Evidence filed: Yes / Not yet
Pupil response β my next step:Ring this yourself — an adult may write your words if you ask.
How I answered it — ring one:👉pointed🗣said it✋showed🖼picture🔁tried again🎬filmedNothing yet is a real answer — leave it blank. Pass is always allowed.Filmed or photographed: work, not faces, unless consent is filed.R — adult initials that they received it: ____________