Lesson type: Precision Lens exploration, boundary reasoning and supported practice.
Stepping Stone: round positive integers and decimals to a stated number of significant figures.
NEO Cornerstones: Connection · Movement · Reflection · Creativity · Rest · Nutrition
45-minute shape: Connect 8 · Move 18 · Practise 10 · Reflect/Create 5 · Rest/Nourish 2 · Evidence 2
Choose only the support that helps now. Every route returns you to Rounding to Significant Figures.
What to do: compare the original number with its rounded version. Decide which digits keep the most useful information about size.
What you are trying to notice: rounding changes a number, but the leading digits can preserve its approximate magnitude.
Original value
48,271
Question: Which digits show that both values are about forty-eight thousand?
Try to explain what remains useful before opening Movement.
What to do: choose a number and a precision. Predict the rounded value, then reveal the lens.
What you are trying to notice: the lens begins at the first non-zero digit, keeps the required digits and uses only the next digit to decide.
What to do: use the Boundary Explorer, then complete the reflection sentence.
A zero is significant when...
What you are trying to notice: rounding chooses the nearer of two possible rounded landmarks. The halfway point explains why 5 rounds up.
What to do: create a mini teaching card for one whole number and one decimal.
Use this quiet route. Look away from the screen, then retrieve it in your own words:
find → keep → decide → check the columns
The last step asks one question: are my kept digits still in the columns they started in?
This lesson uses intellectual nourishment. It nourishes attention to magnitude and confidence with crowded numbers.
What to do: choose one whole number and one decimal and create a clear explanation for each.
Filename pattern: NEO_MATH_PRECISION_FirstName_Date
| Criterion | Approaching Proficiency | Developing Proficiency | Proficiency | Refining Proficiency |
|---|---|---|---|---|
| Understanding | Finds a significant digit with support. | Identifies kept and deciding digits. | Explains where significant figures begin. | Explains the different roles of zeros. |
| Application | Begins a rounding attempt. | Rounds familiar values. | Rounds varied integers and decimals accurately. | Transfers the method to an unfamiliar value. |
| Communication | Shows some digits. | Shows a rounding decision. | Makes the method clear. | Creates an explanation another learner could follow. |
| Reflection | Names one thing noticed. | Checks approximate size. | Explains why the result is sensible. | Uses boundary reasoning to justify the decision. |
Use support in this order: 🤔 prompt → 💡 hint → ✅ check → 📖 worked solution.
Worked solution rule: the worked solution stays locked until the learner has used the Socratic prompt, used the hint, and had two tries.
Use the Scratchpad to predict, sketch, test and revise.
You can use this board, paper or another way of recording your thinking. The Scratchpad is optional.
Angles are in degrees. Examples: 9 × sin(37) = 5.42; sin⁻¹(0.5) = 30