Science lesson plan · 9th grade (Year 10 in England) · 45 minutes
Accuracy, precision, errors and significant figures
Working scientifically
CCSS NGSS.SEP 5CCSS NGSS.HS-PS1-7England: KS4 Working scientificallyEngland: KS4 Combined Science: Working scientifically
Objective and success criteria
Students will: Accuracy, precision, errors and significant figures.
- 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: Repeat readings, means and anomalies; Converting units
Leads to: the next skill in this area.
Materials: Simple equipment for a fair test, Results table template, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Repeat readings, means and anomalies; Converting units). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- A group measured the time for a ball to roll down a ramp three times: 37, 37 and 39 s. What is the mean? Give your answer to 1 decimal place. → 37.7 sPrompt: Add the three readings.
- Convert 10 m into cm. → 1000 cmPrompt: How many cm are in 1 m?
- Four repeat readings of the time for a ball to roll down a ramp (s): 36, 22, 23, 24. Which reading is anomalous (does not fit the pattern)? (36 / 24 / 22 / 23) → 36Prompt: Most of the readings are close together.
Hook · 5 min
- Show a simple experiment with one thing changed and ask what makes it a fair test.
- Share the objective: Accuracy, precision, errors and significant figures. 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: A balance shows 0.3 g when nothing is on it. What kind of error is this?
- Step 1: A scale that does not start at zero adds the same error every time: a systematic (zero) error.
- Step 2: So the answer is: a zero error (a systematic error)
- Answer: a zero error (a systematic error)
- 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.
- What is the resolution of a ruler marked in millimetres? (1 cm / 0.1 mm / 1 mm / 1 m) → 1 mmPrompt: Resolution is the smallest change the instrument can show.
- A balance reads −0.3 g with nothing on it. With a rock on it, it reads 50.8 g. What is the true mass of the rock, in g? → 51.1 gPrompt: The zero error is included in every reading.
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.
- A calculator gives a density of 0.080829. Write it to 3 significant figures. → 0.0808Prompt: Count from the first non-zero digit.
- A balance shows 0.3 g when nothing is on it. What kind of error is this? (a zero error (a systematic error) / a random error / an anomalous result / no error) → a zero error (a systematic error)Prompt: It shifts every reading by the same amount.
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: Repeat readings, means and anomalies.
- Use concrete materials: simple equipment for a fair test.
- 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-9.
Free lesson plan from eurekami.com/lesson-plan-builder