Use one half as a benchmark, and know when that benchmark cannot finish a comparison.
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: Compare 7/12 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c2: Compare 3/8 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c3: Compare 4/8 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c4: Compare 5/6 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c5: Compare 2/5 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c6: Compare 6/10 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c7: Compare 3/7 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
c8: Compare 5/10 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
s1: Compare 1/4 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
s2: Compare 2/4 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
s3: Compare 3/4 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
s4: Compare 1/3 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
h1: Explain where 7/12 belongs without dividing.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
Look for in the response:
- Identify 6/12 as one half.
- Compare seven twelfths with six twelfths without decimal division.
- Place 7/12 above one half.
h2: Name two fractions below half with different denominators.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
Look for in the response:
- Name two fractions with different denominators.
- Make both fractions strictly below one half.
- Verify each using a model or 2 × numerator < denominator.
h3: Can the benchmark alone compare 3/4 and 5/6?
Watch for: Compares unlike fractions using only the numerator, denominator, or an insufficient shared benchmark.
Try: Rename 2/3 and 3/4 as 8/12 and 9/12 on identical wholes. Compare the counts of twelfths. If both fractions lie above one half, ask for this additional evidence before ordering them.
Look for in the response:
- State that being above one half does not by itself order 3/4 and 5/6.
- Supply additional comparison evidence, such as 9/12 and 10/12.
- Conclude 3/4 < 5/6.
h4: Invent a fraction between one half and one.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
Look for in the response:
- Choose a fraction strictly greater than 1/2.
- Verify that the same fraction is strictly less than 1.
- Justify both bounds with equal parts, a line, or numerical inequalities.
e1: Compare 7/12 and 1/2. Choose <, =, or >. The wholes are the same size.
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
e2: How does twice the numerator help?
Watch for: Judges position relative to one half from numerator or denominator alone.
Try: For a/b, compare two copies of a selected parts with all b parts. If 2a is less than, equal to, or greater than b, the original fraction is below, at, or above one half. Test 3/7 by comparing 6 with 7.
Look for in the response:
- Relate doubling the numerator to two copies of the fraction.
- Compare that doubled count with the denominator representing one whole.
- Explain the below/equal/above-half decisions, including 14 > 12 for 7/12.