What to do: You run the bakery. For each order, divide the fractions to find how many servings you can make. Use the tools, type your answers, then press Check My Work.
One 45–55 minute period. Suggested flow: activate prior knowledge — "what does division mean?" (3 min) → Orders 1–2 together as a class, modeling keep–change–flip on the board (15 min) → Orders 3–5 independently or in pairs (15 min) → Order 6 (reasoning backwards) as a class challenge (7 min) → Check My Work, discuss, save deliverable (10 min). Two-day option: Day 1 = Orders 1–4 with visual bar and KCF; Day 2 = Orders 5–6, reflection, and save.
Order 1 (visual bar) and Order 4 (drag-and-drop match) work especially well as pair activities. Orders 2, 3, and 5 are best done individually to check each student's procedural fluency. Order 6 (working backwards) can spark good small-group discussion: "What do we need to divide 1/2 by to get 4?"
You have 1 whole tray. Each cookie needs 1/4 of the tray.
Tap the tray to cut it into fourths. How many cookies can you make? That is 1 ÷ 1/4.
Solve 3/4 ÷ 1/8.
Keep 3/4. Change ÷ to ×. Flip 1/8 to its reciprocal. Then type the whole-number answer.
You have 6 cups of flour. Each bag holds 3/4 cup.
How many bags can you fill? Solve 6 ÷ 3/4.
Drag each answer tile to the matching problem. Keyboard: press a tile, then press a slot. (Answers are whole numbers.)
Solve 2/3 ÷ 4.
Dividing by a whole number makes a smaller piece. Write the answer as a fraction in lowest terms.
A chef has 1/2 pan of brownies and wants to make exactly 4 servings.
Pick the serving size so that 1/2 ÷ (serving) = 4.
| Skill | Expert (4) | Proficient (3) | Developing (2) | Beginning (1) |
|---|---|---|---|---|
| Whole ÷ Unit Fraction Order 1 · 6.NS.A.1 |
Correctly solves 1 ÷ 1/4 = 4; explains using a visual model (tray cut into fourths). | Correctly solves 1 ÷ 1/4 = 4. | Sets up the problem correctly but makes a calculation error (e.g., answers 1/4 instead of 4). | Cannot set up or solve a whole number divided by a unit fraction. |
| Reciprocal / Keep–Change–Flip Order 2 · 6.NS.A.1 |
Correctly identifies reciprocal as 8/1 and computes 3/4 ÷ 1/8 = 6; explains each KCF step. | Correctly identifies reciprocal and computes the correct answer. | Finds the reciprocal correctly but makes a multiplication error, or vice versa. | Cannot identify reciprocal or apply KCF without significant help. |
| Whole Number ÷ Fraction (Word Problem) Order 3 · 6.NS.A.1 |
Correctly solves 6 ÷ 3/4 = 8 and connects the answer to context ("8 bags can be filled"). | Correctly solves 6 ÷ 3/4 = 8. | Sets up 6 ÷ 3/4 but makes an error (e.g., 6 × 3/4 = 4.5 instead of using KCF). | Does not recognize this as a division problem. |
| Fraction ÷ Fraction (Matching) Order 4 · 6.NS.A.1 |
Correctly matches all three problems to their answers (2, 6, 10) and can verify each by multiplying back. | Correctly matches all three problems. | Matches at least two of the three correctly. | Cannot match correctly; fewer than two correct. |
| Fraction ÷ Whole Number Order 5 · 6.NS.A.1 |
Correctly solves 2/3 ÷ 4 = 1/6 in lowest terms; explains that dividing a fraction by a whole number makes it smaller. | Correctly solves 2/3 ÷ 4 = 1/6 in lowest terms. | Sets up correctly but does not reduce to lowest terms (e.g., writes 2/12). | Cannot set up or solve fraction divided by a whole number. |
| Reasoning Backwards Order 6 · 6.NS.A.1 |
Correctly identifies 1/8 pan as the serving size; explains the reasoning (1/2 ÷ 4 = 1/8). | Correctly selects 1/8 pan. | Shows understanding that the serving size should be small but selects incorrect answer. | Cannot reason backwards from the quotient to the divisor. |
Sample reflection: "Dividing fractions means finding how many equal groups of the second fraction fit inside the first. Keep–change–flip works because multiplying by the reciprocal is the same as dividing. This is like asking 'how many 1/4-cup scoops fit in 3/4 cup?' — the answer is 3."
Answer in 2–3 sentences:
Explain in your own words: why does dividing a fraction by a fraction sometimes give an answer bigger than the original fraction? Use an example from the bakery orders to support your explanation.