1 · Count a distance
Choose “Count intervals, then place the point”. Set 4 intervals per whole and place the point at 3/4. Predict the number of intervals travelled.
Open model lab ↗Build, check and explain: fraction model partners
A 20-minute Grade 4 partner station with three model challenges: count a distance, prove equivalence and compare amounts when the whole changes.
For two learners sharing one device during a maths centre or supported home practice.
Have this ready
One browser, paper and a pencil per pair. Download the record sheet first. Each learner predicts, builds or checks, then explains; swap roles between challenges.
Teaching sequence
Assign roles and predict
One learner controls the model; the other checks the whole and equal parts. Both predict the answer on paper.
Build three models
Allow about five minutes per challenge. Use the named task in each lab, check the answer and record the evidence. Swap roles each time.
Transfer to paper
Close the controls. Compare the two ribbons in the final question, separating fraction names from physical lengths.
Open each challenge
Keep your record sheet beside you. The labs open in a new tab so you can return here for the next challenge.
2 · Prove equivalent amounts
Choose “Prove equivalent amounts”. Use 12 cm wholes, 2/3 on A and 4/6 on B. Predict the shaded length.
Open model lab ↗3 · Change the whole
Choose “Check the size of the whole”. Set A to 12 cm with 1/2 shaded and B to 24 cm with 1/4 shaded. Compare lengths and fraction names.
Open model lab ↗Materials for your group
Student pages and teacher answers are separate. Download an HTML file to keep or use your browser to print or save as PDF.
The tasks, ready to use
Read aloud, copy onto a board or use the separate student download. Open an answer only when you are ready to discuss it.
Partner routine
One partner builds the model and the other checks the unit. Swap roles after each challenge. Predict on paper before using the controls; record a model or sketch and an explanation afterwards.
roles. Write your prediction, build the model, use Check model and answer, then explain any change in your thinking. Save an SVG of one completed model or draw it on this sheet.
Challenge 1 · Count intervals, then place the point
Use the Number Line Lab and its first task.
model-1. Set 4 equal intervals per whole. Place a point at 3/4. How many intervals did you travel from zero?
Answer & teaching response
3. The five tick marks from 0 through 1 enclose four intervals. Travel three intervals; the point marks the endpoint.
- The model matches the whole, partitions and selected amounts in the task.
- The answer includes the correct unit or refers to the requested count.
- The explanation connects the model to the answer.
Follow-up: Counting zero as the first interval.
explain-1. Before building: what do you predict? After checking: sketch the model and explain which part of it supports your answer.
Answer & teaching response
Accept a prediction followed by a corrected, accurate explanation; a changed prediction is useful evidence of learning.
Challenge 2 · Prove equivalent amounts
Use the Fraction Strip Lab; choose “Prove equivalent amounts”.
model-2. Use 12 cm wholes. Show 2/3 on strip A and 4/6 on strip B. How many centimeters are shaded on each?
Answer & teaching response
8. Both wholes are 12 cm. Two thirds and four sixths each measure 8 cm; both shaded endpoints agree.
- The model matches the whole, partitions and selected amounts in the task.
- The answer includes the correct unit or refers to the requested count.
- The explanation connects the model to the answer.
Follow-up: Adding the same number to numerator and denominator.
explain-2. Before building: what do you predict? After checking: sketch the model and explain which part of it supports your answer.
Answer & teaching response
Accept a prediction followed by a corrected, accurate explanation; a changed prediction is useful evidence of learning.
Challenge 3 · Check the size of the whole
Use the Fraction Strip Lab; choose “Check the size of the whole”.
model-3. Use a 12 cm whole for A and a 24 cm whole for B. Shade 1/2 of A and 1/4 of B. How many centimeters are shaded on each?
Answer & teaching response
6. One half of 12 cm is 6 cm; one quarter of 24 cm is also 6 cm. Different fractions can describe equal lengths when wholes differ.
- The model matches the whole, partitions and selected amounts in the task.
- The answer includes the correct unit or refers to the requested count.
- The explanation connects the model to the answer.
Follow-up: Comparing fraction labels as physical amounts without checking the whole.
explain-3. Before building: what do you predict? After checking: sketch the model and explain which part of it supports your answer.
Answer & teaching response
Accept a prediction followed by a corrected, accurate explanation; a changed prediction is useful evidence of learning.
Try it without the controls
Draw this new situation independently before discussing it.
transfer. A ribbon A is 12 cm long and ribbon B is 24 cm long. One third of A and one sixth of B are coloured. Are the coloured lengths equal? Are the fraction numbers 1/3 and 1/6 equal? Explain both answers.
Answer & teaching response
Both coloured lengths are 4 cm. The fraction numbers are not equal: 1/3 > 1/6. Equal physical lengths here come from different-sized wholes.
- Calculates or models each 4 cm coloured length.
- Separates equality of lengths from inequality of the fraction numbers.
- Names the 12 cm and 24 cm reference wholes.
Use what you notice
The model is correct but the explanation is unclear
Ask the checker to point to the whole, one equal part and the selected amount. Use the record sheet to explain their connection.
Revisit the size of the whole →