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Science lesson plan · 5th grade (Year 6 in England) · 45 minutes

Brighter or dimmer? Changing cells and bulbs

Electricity and magnetism

CCSS NGSS.4-PS3-2England: KS2 Y6 Electricity

Objective and success criteria

Students will: Brighter or dimmer? Changing cells and bulbs.

  • 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: Circuit symbols, cells and voltage; Will the bulb light? Switches, gaps and complete circuits

Leads to: the next skill in this area.

Materials: Circuit kits (cells, wires, bulbs), Circuit symbol cards, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).

Warm-up · 5 min

  • Quick retrieval from earlier learning (Circuit symbols, cells and voltage; Will the bulb light? Switches, gaps and complete circuits). Students answer on mini whiteboards.
  • Show answers together and note who needs support in the main task.
  1. In a circuit diagram, a long thin line next to a short thick line stands for… (a motor / a switch / a cell / a bulb) → a cellPrompt: The long line is the positive terminal.
  2. A gap in a line with a small hinged line (lifted up) stands for… (a bulb / a closed switch / an open switch / a cell) → an open switchPrompt: The gap means the circuit is broken.
  3. A circle with the letter M inside stands for… (a motor / a meter / a mirror / a magnet) → a motorPrompt: The letter is a clue.

Hook · 5 min

  • Show a circuit with a gap and ask why the bulb doesn't light.
  • Share the objective: Brighter or dimmer? Changing cells and bulbs. 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: Two cells are used instead of one, but they are put in facing opposite ways. What happens to the bulb?
  • Step 1: Cells facing opposite ways cancel out their push.
  • Step 2: So the answer is: It does not light, because the cells push against each other.
  • Answer: It does not light, because the cells push against each other.
  • 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.
  1. Why might a bulb blow if you add too many cells? (Too much current makes the filament overheat and break. / The wires disappear. / The cells get cold. / Bulbs only work with one cell.) → Too much current makes the filament overheat and break.Prompt: Each bulb is designed for a certain voltage.
  2. True or false? Adding bulbs to a series circuit makes each bulb dimmer. (True / False) → TruePrompt: Cells push; bulbs share the push.

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.
  1. True or false? Adding cells to a series circuit makes the bulbs brighter. (True / False) → TruePrompt: Cells push; bulbs share the push.
  2. Why might a bulb blow if you add too many cells? (The cells get cold. / Too much current makes the filament overheat and break. / Bulbs only work with one cell. / The wires disappear.) → Too much current makes the filament overheat and break.Prompt: Each bulb is designed for a certain voltage.

Watch out for

  • Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
  • Remembering facts without the reason: ask "why?" and "what is the evidence?"

Support and stretch

Support

  • Review first: Circuit symbols, cells and voltage.
  • Use concrete materials: circuit kits (cells, wires, bulbs).
  • Give the first step of each question, or a partly worked example to finish.
  • Pair with a confident partner for the guided practice.

Stretch

  • 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/science/grade-5.

Free lesson plan from eurekami.com/lesson-plan-builder

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Brighter or dimmer? Changing cells and bulbs

Name

Date

Score/ 8

  1. Question 1

    A series circuit has 3 cells and 2 bulbs. It is changed to 2 cells and 2 bulbs (all the same type). How bright is each bulb now?

    • A. brighter than before
    • B. the same as before
    • C. dimmer than before
  2. Question 2

    True or false? Circuit diagrams use standard symbols.

    • A. True
    • B. False
  3. Question 3

    Why might a bulb blow if you add too many cells?

    • A. Bulbs only work with one cell.
    • B. The wires disappear.
    • C. Too much current makes the filament overheat and break.
    • D. The cells get cold.
  4. Question 4

    A series circuit has 3 cells and 1 bulb. It is changed to 3 cells and 2 bulbs (all the same type). How bright is each bulb now?

    • A. brighter than before
    • B. the same as before
    • C. dimmer than before
  5. Question 5

    True or false? Adding bulbs to a series circuit makes each bulb dimmer.

    • A. True
    • B. False
  6. Question 6

    A buzzer is too quiet. What change to the circuit will make it louder?

    • A. Use longer wires.
    • B. Open the switch.
    • C. Add another buzzer.
    • D. Add another cell.
  7. Question 7

    A series circuit has 2 cells and 1 bulb. It is changed to 4 cells and 2 bulbs (all the same type). How bright is each bulb now?

    • A. brighter than before
    • B. the same as before
    • C. dimmer than before
  8. Question 8

    True or false? The number of cells makes no difference to brightness.

    • A. True
    • B. False

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Answer key: Brighter or dimmer? Changing cells and bulbs

  1. 1. C. dimmer than before

  2. 2. A. True

  3. 3. C. Too much current makes the filament overheat and break.

  4. 4. C. dimmer than before

  5. 5. A. True

  6. 6. D. Add another cell.

  7. 7. B. the same as before

  8. 8. B. False