# Metric Mastery

 Metric Mastery Nature of Science & Lab Event Forum Threads 2013 Tests 2013 There are no images available for this event This event was not held last year in Division B This event was not held last year in Division C

Metric Mastery is a Division B event currently being run in 2013, which tests the students' ability to quickly and accurately estimate and measure the physical properties of objects in metric units. Properties to be measured can include mass, volume, density, area, force, distance, time, and temperature.

This will usually be a station based event. In the first part of the competition, students will estimate the properties asked for of an object in or in less than 30 seconds, then move on when they are given directions to do so. In the second part, students will usually move back to the same objects with measuring tools, and accurately measure them.

## Part One: Estimate

• 30 seconds is the recommended time that the event supervisors should give for each estimation.
• Students may not use any tools to help them estimate.
• Such "tools" include watches, writing implements, electronic devices, notes, fingers, pieces of paper, pencils, clothing, etc. Must some of these items be brought in (fingers, clothing), they cannot be utilized in the competition.
• The event supervisor will provide pencils.
• Students may not touch, feel, or "heft" the objects, unless otherwise explicitly stated.
• Use correct units. The supervisor will identify which units to use.
• Follow the correct rotation order.
• Make sure students understand that their first station will not necessarily be number one on their paper. They might be starting at any number.
• No calculators are allowed.
• Quick conversion: if you can estimate mass well but are not as good at estimating force, you can divide grams by 100 or multiply kg by 10 to get Newtons. You will automatically be off by 2%; however, if their mass estimate is very accurate, they may still be within 10% of the correct measurement of force.
• Scoring system for the estimation section of the competition:
• 5 points if within 5% of measured value
• 3 points if within 10% of measured value
• 1 points if within 20% of measured value
• Not in any of the above, 0
• If in one of the categories, only points for that category are awarded (if you land within 3%, you do not get 5+3+1 points)

## Part Two: Measure

• 60 seconds is the recommended time that the event supervisors should give for each measurement.
• Use correct units. The supervisor will identify which units to use.
• Measure to the precision of the instrument plus one estimated digit.
• Follow the correct rotation order. The first station you visit may not necessarily be number one on your paper. You could start at any number.
• Students must realize that not all graduated cylinders are the same, nor are all rulers, or any other measurement instrument. They should practice determining what degree of precision to include in their measurements.
• Students should practice using a variety of measuring instruments.
• Practice using a vernier scale such as seen on calipers.
• Practice using a vernier caliper to find internal diameter (ID), outside diameter (OD) and depth.
• Practice using micrometers.
• Practice using instruments with a reversed scale such as on some pipettes.
• Practice using double pan or Harvard Trip balances.
• Practice calculating mass by using tare mass.
• Although it is a good practice to calibrate instruments before they make measurements, do not assume you should at a competition. Check with an event supervisor before adjusting any instrument!
• Evaluate rulers and meter sticks carefully before you begin measurement, if there isn't a true 0, start measurement at 1 and then subtract 1 from the measurement.
• Scoring system for the measurement section of the competition:
• Regionals: correct if within $\pm3$ of the estimated digit
• States: correct if within $\pm2$ of the estimated digit
• Nationals: correct if within $\pm1$ of the estimated digit

## Other Precautions

Make sure to:

• return measuring devices to their original position
• clean up any spills
• never alter equipment without first asking an event supervisor (zeroing a balance, etc.-can result in disqualification)

Any of these violations will result in a 10 point penalty, each time.

• Whether doing math or measuring, be sure to use significant figures if your event supervisors want you to.

## Practice and Resources

Plastic vernier calipers can be picked up at many hardware stores. Instrument help online: There are many sites available to learning how to use tools such as a micrometer or a vernier caliper. If you use Google to search for a "vernier scale", you will find many usable sites.

A good way to practice this event is to just estimate then measure everything in site. Make sure to give yourself obscure units (e.g. a door in cm and a doorknob in km) and hard properties!