Math lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Find start and end times
Measurement
CCSS 3.MD.A.1England: Y3 MeasurementEngland: Y4 Measurement
Objective and success criteria
Students will: Find start and end times.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Elapsed time; Tell time to the nearest minute
Leads to: Elapsed time in hours and minutes, including across noon; Read bus and train timetables
Materials: Rulers, scales and measuring jugs, Clock faces, Conversion chart, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Elapsed time; Tell time to the nearest minute). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- How many minutes are there from 8:40 to 10:10 (same morning)? → 90Prompt: Jump to the next o'clock, then count whole hours, then the extra minutes.
- How many minutes are there from 6:05 to 8:30 (same morning)? → 145Prompt: Jump to the next o'clock, then count whole hours, then the extra minutes.
- How many minutes are there from 7:10 to 8:55 (same morning)? → 105Prompt: Jump to the next o'clock, then count whole hours, then the extra minutes.
Hook · 5 min
- Ask the class to estimate the length of the room or the weight of a bag before measuring it.
- Share the objective: Find start and end times. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Chloe's coding club lasted 40 min and finished at 2:10. What time did it start? Type it like 2:35.
- Step 1: 2:10 − 40 min = 1:30
- Answer: 1:30
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Sam's coding club lasted 2 h 20 min and finished at 5:30. What time did it start? Type it like 2:35. → 3:10Prompt: Count back from the end time.
- Lucia's swimming lesson lasted 1 h 45 min and finished at 5:50. What time did it start? Type it like 2:35. → 4:05Prompt: Count back from the end time.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Priya's baking session lasted 1 h 55 min and finished at 9:20. What time did it start? Type it like 2:35. → 7:25Prompt: Count back from the end time.
- Chloe's baking session lasted 1 h 25 min and finished at 2:55. What time did it start? Type it like 2:35. → 1:30Prompt: Count back from the end time.
Watch out for
- Measuring from the end of the ruler instead of zero.
- Converting units the wrong way (multiplying instead of dividing).
Support and stretch
Support
- Review first: Elapsed time.
- Use concrete materials: rulers, scales and measuring jugs.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Elapsed time in hours and minutes, including across noon; Read bus and train timetables.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-3.
Free lesson plan from eurekami.com/lesson-plan-builder