Measurement 2.2
Using Units to Measure Well
Using Units to Measure Well
WATCH: How Do We Measure Consistently?
WATCH: How Do We Measure Consistently?
DISCUSS: Five Big Ideas in Direct Measurement
DISCUSS: Five Big Ideas in Direct Measurement
Craig and Patrick describe five big ideas that underpin direct measurement and our understanding of the unit. You can review them here. Are there any ideas that might surprise your students? Or you?
Craig and Patrick describe five big ideas that underpin direct measurement and our understanding of the unit. You can review them here. Are there any ideas that might surprise your students? Or you?
How do you react to the statement: All measurements are an approximation? Agree or disagree? Talk about it. Why might this be an important idea for students to understand?
How do you react to the statement: All measurements are an approximation? Agree or disagree? Talk about it. Why might this be an important idea for students to understand?
When we ask students to "measure accurately" what are we really asking for? What elements make a measurement trustworthy?
When we ask students to "measure accurately" what are we really asking for? What elements make a measurement trustworthy?
Share your thinking and wonderings in the Collaborative Notebook.
Share your thinking and wonderings in the Collaborative Notebook.
Optional: Want to Go Deeper?
Optional: Want to Go Deeper?
Read more about the notion that all measurements are approximate or about the skills needed to measure reliably. Use these readings to further clarify your thinking about what it means to use units to directly measure.
Read more about the notion that all measurements are approximate or about the skills needed to measure reliably. Use these readings to further clarify your thinking about what it means to use units to directly measure.
TASK: Overestimate or Underestimate?
TASK: Overestimate or Underestimate?
To measure reliably is to get the same result each time. We want our measurements to be trustworthy and useful for the purpose for which we are measuring.
To measure reliably is to get the same result each time. We want our measurements to be trustworthy and useful for the purpose for which we are measuring.
This means:
This means:
1. We make sure our instrument matches the unit well (e.g., the instrument is the same size as the unit)
1. We make sure our instrument matches the unit well (e.g., the instrument is the same size as the unit)
2. We consistently repeat our instrument (e.g., the instrument is the same size each time).
2. We consistently repeat our instrument (e.g., the instrument is the same size each time).
3. We make sure that the object is fully matched but no more (e.g., we minimize gaps or overlaps).
3. We make sure that the object is fully matched but no more (e.g., we minimize gaps or overlaps).
Take a look at ten scenarios (click on screenshot to the left to enlarge) each with a measurement error. Discuss each scenario and decide if the error would result in an overestimate (where the measurement taken is greater than the actual measurement) or an underestimate (where the measurement taken is less than the actual measurement). Then describe the problem and why it will result in the error.
Take a look at ten scenarios (click on screenshot to the left to enlarge) each with a measurement error. Discuss each scenario and decide if the error would result in an overestimate (where the measurement taken is greater than the actual measurement) or an underestimate (where the measurement taken is less than the actual measurement). Then describe the problem and why it will result in the error.
You can download your own editable Google Doc (must be signed into a Google account) or print this PDF.
You can download your own editable Google Doc (must be signed into a Google account) or print this PDF.
Optional: Check your Ideas
Optional: Check your Ideas
No guarantees, but here are our proposed solutions for the Gaps and Overlaps activity. See what you think.
No guarantees, but here are our proposed solutions for the Gaps and Overlaps activity. See what you think.
CONSOLIDATE
CONSOLIDATE
Summarize some of the ideas you or your students would find helpful in the Collaborative Notebook. And if you have questions, comments or additional ideas, we'll look forward to reading them.
Summarize some of the ideas you or your students would find helpful in the Collaborative Notebook. And if you have questions, comments or additional ideas, we'll look forward to reading them.
