Name an equal share of a unit fraction relative to the original whole.
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.
Ready to continue
e1 meets its criterion: e1 gives 1/6 for 1/2 ÷ 3. e2 also meets its criterion: e2 names the original whole, rather than the shaded half, as the reference for the final share.
Continue to the linked next lesson. Contrast finding the size of one share with counting fixed-size servings.
Next lesson: How Many Servings Revisit the calculation or model
e1 does not yet meet this criterion: e1 gives 1/6 for 1/2 ÷ 3.
Ask the learner to explain the attempt, then use the matching diagnostic probe to identify the difficulty. Work through the focused reteach below and its check. Use the linked short intervention if the difficulty persists; retry e1 and e2 before moving on.
Open the linked short intervention Strengthen the explanation
e1 meets its criterion, but e2 does not yet show this evidence: e2 names the original whole, rather than the shaded half, as the reference for the final share.
Ask the learner to label both “one original whole” and “amount being shared” on e1, then explain why one third of the half is one sixth of the whole.
Open the linked short intervention 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: Calculate 1/2 ÷ 3. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c2: Calculate 1/3 ÷ 2. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c3: Calculate 1/4 ÷ 3. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c4: Calculate 1/5 ÷ 2. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c5: Calculate 1/6 ÷ 4. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c6: Calculate 1/8 ÷ 3. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c7: Calculate 1/3 ÷ 5. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
c8: Calculate 1/4 ÷ 4. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
s1: Calculate 1/2 ÷ 2. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
s2: Calculate 1/3 ÷ 2. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
s3: Calculate 1/4 ÷ 2. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
s4: Calculate 1/2 ÷ 4. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
h1: Explain 1/2 ÷ 3 with a model.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
Look for in the response:
- Draw one whole and identify its half.
- Split that half into three equal shares.
- Relate one share to the original whole as 1/6, explaining that six such shares fill it.
h2: Check one sixth as the share by multiplication.
Watch for: Confuses the number of equal groups with the size of each group.
Try: Draw three separate bags, each holding 2/5 cup. Label “3 groups” and “2/5 cup per group.” Count six fifth-cup pieces in total and connect the drawing to 2/5 + 2/5 + 2/5.
Look for in the response:
- Identify three shares of size 1/6.
- Write or model 3 × 1/6.
- Recover 3/6 = 1/2, the quantity originally shared.
h3: Why is the share less than the starting unit fraction?
Watch for: Assumes multiplication always enlarges a positive amount.
Try: Keep a 3/4-meter ribbon as the starting amount. Compare half a copy, one copy, and two copies. Record 3/8, 3/4, and 3/2 meters, then relate each change to a factor below, equal to, or above one.
Look for in the response:
- Specify that the starting amount is positive and shared among more than one recipient.
- Explain that the equal shares together make the original amount.
- Conclude each share is smaller than that amount, using 1/2 ÷ 3 if helpful.
h4: Write a story for 1/4 ÷ 3.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
Look for in the response:
- Use a starting amount of 1/4 of a named unit.
- Share it equally among three recipients or groups.
- State that each receives 1/12 of the original unit.
e1: Calculate 1/2 ÷ 3. Show a model or your reasoning.
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
e2: What whole is used to name the final share?
Watch for: Names a share relative to the shaded fraction instead of the original whole.
Try: Shade half of a whole strip and divide that half into three equal shares. Extend the same cuts across the unshaded half: six shares fill the original whole, so each is 1/6. Check 3 × 1/6 = 1/2.
Look for in the response:
- Name the original whole as the reference for the answer.
- Distinguish one third of the shaded half from one third of the original whole.
- Explain that e1 gives 1/6 of the original whole.