Metric Mastery B

[caseyotis]

Measure to the precision of the instrument plus one estimated digit.

I saw this on the Wiki under the Measurement section. What exactly does it mean?

[Luo]

Measure to the precision of the instrument plus one estimated digit.

I saw this on the Wiki under the Measurement section. What exactly does it mean?

So let's say that the smallest marks on a ruler are 0.1 cm apart (this is what "precision of the instrument" refers to). You would record your answer out to the nearest 0.01 cm, but since the ruler's smallest markings are 0.1 cm apart, you would have to estimate the hundredths place (this is what "plus one estimated digit" refers to).

As an example, let's say that you're measuring a line segment with such a ruler, and the line segment ends between the 5.1 cm and 5.2 cm marks. You would then estimate the hundredths digit, so if you estimated that the line segment extended to exactly halfway between those two marks, you would record 5.15 cm as your answer.

[caseyotis]

Measure to the precision of the instrument plus one estimated digit.

I saw this on the Wiki under the Measurement section. What exactly does it mean?

So let's say that the smallest marks on a ruler are 0.1 cm apart (this is what "precision of the instrument" refers to). You would record your answer out to the nearest 0.01 cm, but since the ruler's smallest markings are 0.1 cm apart, you would have to estimate the hundredths place (this is what "plus one estimated digit" refers to).

As an example, let's say that you're measuring a line segment with such a ruler, and the line segment comes out to between the 5.1 cm and 5.2 cm marks. You would then estimate the hundredths digit, so if you estimated that the line segment extended to exactly halfway between those two marks, you would record 5.15 cm as your answer.

Ah, I see. That makes sense. Thank you!

[sjwon3789]

Has anyone competed in a competition such that:

The measurement portion had a meter stick, with no marks on it...I had to measure a long brick of wood with it.
One had a picture of Virginia in a map, with a scale (too blurry to read it...). You had to find the area of Virginia land.
There were also other messed up stuff but I can't remember. Oh, it was too messed up that there was a broken graduated cylinder so it was leaking. I thought they MEANT to do that Looooooool.

[awesome90220]

Has anyone competed in a competition such that:

The measurement portion had a meter stick, with no marks on it...I had to measure a long brick of wood with it.
One had a picture of Virginia in a map, with a scale (too blurry to read it...). You had to find the area of Virginia land.
There were also other messed up stuff but I can't remember. Oh, it was too messed up that there was a broken graduated cylinder so it was leaking. I thought they MEANT to do that Looooooool.

To answer your question- No
Is the only way to "study" for this event to practice if so *silently curses*

[Skink]

Hahahaha...that supervisor's tasks I find amusing, admittedly, but, while allowed by the rules, are outside the purposes of the event in my opinion. See, there are three or four conflicting approaches (1 and 2 are similar) one can take to running this event:

1. measuring everyday objects with typical instruments
2. measuring odd objects with typical instruments
3. measuring everyday objects with typical instruments and reporting answer in unusual units (e.g. cubic dekameters).
4. measuring everyday objects with atypical instruments (like mentioned above)

I tend to lean towards 1 and 2 myself but dabble in 3 or 4. The question I raise is how did the rule writers intend for the event to be done? They may have intended for number 3; I don't know. I am doubtful they intended for number 4, though. The scoring guidelines are the way they are so supervisors can check that you know how to accurately read a ruler or any other instrument. Providing you with a ruler sans marks assesses nothing, really. It's gimmicky. It goes without saying 2, 3, and 4 are higher level tasks that I'd expect at the State level, not necessarily Regionals. But who knows? This event seems pretty unpredictable.

So, with some much uncertainty about what the event will be like for you at your competition, I don't know what the best approach to studying is! What I do know is this is very much a 'do it' sort of event. You need to make estimations followed by measurements of real objects. I would try to obtain any common instruments that you are missing.

[hscmom]

For a box that small, you could try imagining packing cubes of 1cm x 1cm x 1cm and seeing how many would fit. If the event supervisors ask for the answer in liters, then imagine cubes of 10cm x 10cm x 10cm. It's worth a shot and sort of works for me.

I'm coaching WIDI and needed some fresh ideas so a few days ago I went to Dollar Tree and found that they had foam blocks (for a buck, of course) and they are 10 cm X 10 cm X 10 cm which means they are a liter. If you can find these at your dollar store or hobby store, they are good for staring at and learning the liter. "How many craft blocks would fit in this shoe box?"

[hscmom]

That said, we're pretty nervous about the competition as Metric's not been an event in years and I've never coached it before. I think our pair is doing okay, but I have no idea how they compare to the other teams' students. Ask me in a few days when we're either happy with the event or wondering what went wrong...

Hey, you were supposed to ASK me! Good job Juan and Stephanie for getting a silver in this at Regionals. States will be 10 times harder though!

[sr243]

I have a question about significant digits. Since it says division B doesn't need to know significant digits, how would you express the area of 1.01cm (estimation digit included) x 1.04cm? Do you have to write 1.05 which is the answer with significant digits or can you write 1.0504? Basically, I feel like if you don't use significant digits, the number is written with too many digits which makes it seem more precise than it is. However, rules say you don't need to know significant digits. Can anyone clarify or should I send a rules clarification? (States is this weekend)

[Skink]

The sig figs policy says that division B doesn't need them unless specified by the specific event rules, if I recall. This event calls for reporting answers to the first uncertain digit, so sig fig rules apply far as my understanding goes. Your product would be 1.05 square centimeters.