\text{Key: } 40 \\mid 0 = 400\\text{ cm}$$\n\nThis tells the reader that a stem of $40$ combined with a leaf of $0$ represents $400\\text{ cm}$."}]}],"generatedAt":"2026-06-12T13:43:38.887Z","modelVersion":"gemini-3.5-flash","explanationVersion":"v2"},"firstAttemptFullMarks":null},{"id":"354fe0b9-7328-47ce-98e8-b369a5bda233","revisionId":"76a53148-a4d6-46f9-a8ed-a4142e0e67fb","questionNumber":null,"questionType":"LA","specification":"Here are the delivery times, in minutes, for 20 different parcels.\n\n| | | | | | | | | | |\n|----|----|----|----|----|----|----|----|----|----|\n| 15 | 32 | 28 | 41 | 22 | 19 | 35 | 26 | 44 | 20 |\n| 18 | 30 | 24 | 27 | 39 | 17 | 21 | 33 | 25 | 31 |","difficulty":2,"difficultyBand":"medium","totalMarks":5,"sourceTitle":null,"calculatorUse":"non_calc","parts":[{"id":"82d3bb1e-1eb2-4d7e-84c9-e9fa811cdc70","label":"a","content":"Draw an ordered stem and leaf diagram to show this information. You must include a key.","markscheme":"- Correct stems 1, 2, 3, 4 B1\n- All leaves correct and ordered B1\n- Correct key, e.g., $1|5 = 15$ minutes B1\n\n| Stem | Leaf |\n| :--- | :--- |\n| 1 | 5 7 8 9 |\n| 2 | 0 1 2 4 5 6 7 8 |\n| 3 | 0 1 2 3 5 9 |\n| 4 | 1 4 |","marks":3,"order":0,"markingRubric":{"totalMarks":3,"points":[{"id":"p1","marks":1,"description":"Correct stems 1, 2, 3, 4","code":"B"},{"id":"p2","marks":1,"description":"All leaves correct and ordered","code":"B"},{"id":"p3","marks":1,"description":"Correct key with minutes","code":"B"}],"finalAnswers":["1|5 = 15 minutes"],"generatedAt":"2026-05-06T13:59:16.191Z","modelVersion":"gemini-3-flash-preview"},"explanation":{"methods":[{"id":"ordered_stem_and_leaf","label":"Build an ordered stem-and-leaf diagram","steps":[{"type":"text","order":0,"title":"Choose the stems","content":"Use each **tens digit** as a stem. The data run through the tens, twenties, thirties and forties, so write the stems vertically as $1$, $2$, $3$ and $4$. This earns **B1** for the correct stems.","highlights":[{"text":"Draw an ordered stem and leaf diagram","location":"specification"}]},{"type":"text","order":1,"title":"Sort the leaves","content":"For each time, place its **units digit** beside the matching tens stem. Sort the leaves from smallest to largest across every row. For example, $15$ gives stem $1$ and leaf $5$."},{"type":"text","order":2,"title":"Draw the diagram","content":"| Stem | Leaf |\n| :---: | :--- |\n| $1$ | $5\\quad 7\\quad 8\\quad 9$ |\n| $2$ | $0\\quad 1\\quad 2\\quad 4\\quad 5\\quad 6\\quad 7\\quad 8$ |\n| $3$ | $0\\quad 1\\quad 2\\quad 3\\quad 5\\quad 9$ |\n| $4$ | $1\\quad 4$ |\n\nAll the leaves are present and in ascending order, earning **B1**. As a quick check, there are $20$ leaves altogether, matching the number of parcels.","highlights":[{"text":"20 different parcels","location":"specification"}]},{"type":"text","order":3,"title":"Include the key","content":"Write a key such as\n\n$$1\\mid 5=15\\text{ minutes}$$\n\nThis explains that the stem is the tens digit and the leaf is the units digit. Including the unit makes the meaning clear and earns the final **B1**.","highlights":[{"text":"You must include a key.","location":"specification"}]}]}],"generatedAt":"2026-07-20T11:25:06.495Z","modelVersion":"gpt-5.6-sol","explanationVersion":"v3"},"options":[]},{"id":"97ee76fb-19cd-4a00-a007-5619f196bf20","label":"b","content":"Work out the median delivery time.","markscheme":"- Identifies the 10th and 11th values as 26 and 27 M1\n- $\\frac{26 + 27}{2} = 26.5$ A1","marks":2,"order":1,"markingRubric":{"totalMarks":2,"points":[{"id":"p1","marks":1,"description":"Identifies the 10th and 11th values in the sorted data set","code":"M"},{"id":"p2","marks":1,"description":"Calculates the average of 26 and 27","code":"A"}],"finalAnswers":["26.5"],"generatedAt":"2026-05-06T13:59:16.191Z","modelVersion":"gemini-3-flash-preview"},"explanation":{"methods":[{"id":"order_and_average","label":"Order and average","steps":[{"type":"text","order":0,"title":"Put times in order","content":"Arrange

Stem and Leaf Questions

Stem and Leaf Questions

Stem and Leaf Questions

Stem and Leaf Questions