Audit fraction exhibits for equal parts, accurate labels, and equivalent values.
The original lesson PDFs remain version 1.0.0. This supplement adds diagnostic probes, teaching responses, and question-specific rubrics. Use the supplement below for the updated guidance.
Ask for an explanation or drawing before choosing a response. A wrong answer alone does not identify its cause.
Question-by-question misconception guide and open-response criteria
Use these as follow-up prompts, then examine the learner’s model or explanation. Open responses may differ from the sample while satisfying the criteria.
c1: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 2 equal parts; 1 parts are shaded altogether.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
c2: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 4 equal parts; 2 parts are shaded altogether.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
c3: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 6 equal parts; 3 parts are shaded altogether.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
c4: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 8 equal parts; 4 parts are shaded altogether.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
c5: Compare 1/2 and 2/4. Choose <, =, or >. The wholes are the same size.
Watch for: Changes one part of a fraction without scaling numerator and denominator by the same factor.
Try: Shade 2/3 of a fixed strip and split each third into two equal parts. Count four shaded sixths out of six. Write ×2 on both arrows and check that the shaded endpoint did not move.
c6: Compare 2/3 and 4/6. Choose <, =, or >. The wholes are the same size.
Watch for: Changes one part of a fraction without scaling numerator and denominator by the same factor.
Try: Shade 2/3 of a fixed strip and split each third into two equal parts. Count four shaded sixths out of six. Write ×2 on both arrows and check that the shaded endpoint did not move.
c7: Compare 3/4 and 6/8. Choose <, =, or >. The wholes are the same size.
Watch for: Changes one part of a fraction without scaling numerator and denominator by the same factor.
Try: Shade 2/3 of a fixed strip and split each third into two equal parts. Count four shaded sixths out of six. Write ×2 on both arrows and check that the shaded endpoint did not move.
c8: Compare 2/2 and 3/3. Choose <, =, or >. The wholes are the same size.
Watch for: Does not recognize that b copies of 1/b make one whole.
Try: Fill one outlined whole with b equal pieces and label the completed whole b/b. Exchange the complete collection for a card labeled 1; do the exchange again with a different partition.
s1: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 2 equal parts; 1 parts are shaded altogether.
Watch for: Treats the denominator as a count of selected pieces instead of the number of equal parts in one whole.
Try: Outline one whole first. Count all the equal pieces that fill it, label one piece 1/b, then repeat that piece until the whole is covered with no gaps.
s2: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 3 equal parts; 1 parts are shaded altogether.
Watch for: Treats the denominator as a count of selected pieces instead of the number of equal parts in one whole.
Try: Outline one whole first. Count all the equal pieces that fill it, label one piece 1/b, then repeat that piece until the whole is covered with no gaps.
s3: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 4 equal parts; 1 parts are shaded altogether.
Watch for: Treats the denominator as a count of selected pieces instead of the number of equal parts in one whole.
Try: Outline one whole first. Count all the equal pieces that fill it, label one piece 1/b, then repeat that piece until the whole is covered with no gaps.
s4: What fraction is shaded? Write its value.
Strip model: 1 same-sized whole, each divided into 4 equal parts; 2 parts are shaded altogether.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
h1: Design two exhibits for one half.
Watch for: Changes one part of a fraction without scaling numerator and denominator by the same factor.
Try: Shade 2/3 of a fixed strip and split each third into two equal parts. Count four shaded sixths out of six. Write ×2 on both arrows and check that the shaded endpoint did not move.
Look for in the response:
- Create two different partitioned exhibits for one half.
- Use equal-sized wholes and equal parts within each exhibit.
- Show that both shaded amounts cover half, such as 1/2 and 2/4.
h2: Curate an exhibit labeled 2/3 on a strip with two of four parts shaded.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
Look for in the response:
- Identify the mismatch between the 2/3 label and two of four shaded parts.
- Repair the label to 2/4 (or 1/2), or redraw thirds with two shaded.
- Explain why the repaired label now matches both total and shaded counts.
h3: Write a museum note about whole fractions such as 3/3.
Watch for: Does not recognize that b copies of 1/b make one whole.
Try: Fill one outlined whole with b equal pieces and label the completed whole b/b. Exchange the complete collection for a card labeled 1; do the exchange again with a different partition.
Look for in the response:
- Explain that 3/3 includes all three thirds.
- State that these equal parts fill one whole.
- Extend the note to fractions such as b/b rather than suggesting all fractions equal one.
h4: Give feedback on uneven partitions without rejecting the artist.
Watch for: Counts pieces without checking equal area.
Try: Keep one rectangle fixed. Draw four unequal pieces beside four equal-area pieces. Ask which set lets every piece be called one fourth, then have the learner repair the unequal partition.
Look for in the response:
- Identify uneven part areas as the mathematical issue.
- Give a specific revision that equalizes the partition sizes.
- Use feedback that addresses the model constructively and preserves an accurate fraction label.
e1: Compare 1/2 and 3/6. Choose <, =, or >. The wholes are the same size.
Watch for: Changes one part of a fraction without scaling numerator and denominator by the same factor.
Try: Shade 2/3 of a fixed strip and split each third into two equal parts. Count four shaded sixths out of six. Write ×2 on both arrows and check that the shaded endpoint did not move.
e2: Give one check you would use before displaying a model.
Watch for: Counts pieces without checking equal area.
Try: Keep one rectangle fixed. Draw four unequal pieces beside four equal-area pieces. Ask which set lets every piece be called one fourth, then have the learner repair the unequal partition.
Watch for: Reverses the shaded count and the total equal-part count.
Try: Use two labels: “equal pieces in one whole” under the bar and “pieces selected” above it. Point to every piece while naming the denominator, then only the selected pieces while naming the numerator.
Look for in the response:
- Name a concrete pre-display check such as equal areas or label-to-count agreement.
- State what feature of the model is inspected, such as the part areas or selected count.
- Use a condition that establishes mathematical accuracy of the fraction exhibit.