Fraction Division Fix-It: Carrot Sticks, Granola Bars, and Garden Plots
Divide unit fractions by whole numbers and whole numbers by unit fractions using correct reasoning about equal shares and how many groups fit.
Read the passages and examples below. Two examples show correct work and three show a common mistake: multiplying when you should divide, or flipping the wrong number. For every answer, check the size: sharing one piece among more people makes each piece smaller; counting how many small pieces fit into wholes makes the number bigger.
The claimed answer 2/5 is bigger than 1/5. Splitting makes pieces smaller: the correct answer 1/10 is the shortest bar.
3 wholes contain six 1/2-size pieces. Dividing by a unit fraction asks how many pieces fit.
Practice questions
- 1
Compute: 1/2 ÷ 4 = ?
- 2
A garden has 3 plots. Each plot is split into 1/3-plot sections. How many 1/3-plot sections are there in all?
- 3
Error analysis: A student says 1/3 ÷ 2 = 2/3. What is the correct answer?
- 4
Error analysis: A student says 2 ÷ 1/4 = 1/2 because 2 is cut in half. What is the correct answer?
- 5
A snack box has 1/2 of a granola bar. The half is shared equally by 4 friends. What fraction of a WHOLE granola bar does each friend get?
- 6
Compare these two answers. Which is larger: 1/2 ÷ 3 or 1/2 ÷ 6? Enter the larger value.
- 7
A garden plan says 2 plots are each split into 1/4-plot sections. How many sections are there?
- 8
Explain the error: A student says 1/4 ÷ 2 = 1/2 because the answer got bigger. What is the correct answer?
- 9
Error analysis: A student says 3 ÷ 1/3 = 1. What is the correct answer?
- 10
Explain the mistake: A student says 1/3 ÷ 2 = 2/6 because they multiplied top and bottom by 2. What is the correct answer?
- 11
Compare these two amounts. Which is larger: 2 ÷ 1/4 or 2 ÷ 1/2? Enter the larger value.
Part of the question set is shown. Generate the whole intervention, freshly themed and with an answer key, for your own class in the product.
