Metric Mastery B

[Pele]

Does anyone know any good methods for estimating mass?

IMO, Mass is more difficult than length and volume. One very simple thing we did is to collect different household things (a can of soup, a pack of index cards, a shoe - you get the idea) and stick them on the scale and write the mass in Sharpie.

Then practice. Heft your mass the same way each time (in other words, if you don't rest your hefting elbow on a table today, don't rest it on there tomorrow).

Agreed. Practice is key.

[awesome90220]

Hey for guessing weight, I've realized that when surface area on your hand is smaller, you'll feel more pressure, meaning you'll feel its heavier. Is there a way to negate this?

[billyhoho]

Hey for guessing weight, I've realized that when surface area on your hand is smaller, you'll feel more pressure, meaning you'll feel its heavier. Is there a way to negate this?

You actually want to make it "feel heavier" since that'll make it the most accurate. By minimizing surface area, you're allowing the calculation of the total weight to be more accurate (since otherwise, it would be "spread" along the whole hand/whatever, making objects seem to weigh less).

[awesome90220]

Hey for guessing weight, I've realized that when surface area on your hand is smaller, you'll feel more pressure, meaning you'll feel its heavier. Is there a way to negate this?

You actually want to make it "feel heavier" since that'll make it the most accurate. By minimizing surface area, you're allowing the calculation of the total weight to be more accurate (since otherwise, it would be "spread" along the whole hand/whatever, making objects seem to weigh less).

Well, what if it's like a cube? Say you used a dice as your reference, and it was, say, 1 gram. Then, at the competition, they give you a big foam dice and ask you to estimate the weight. It seems like, uh, I don't know, maybe 10 grams? But then, if you're doing measurement, you get it to be like 80 grams and you're like: AW MAN D:

[hscmom]

Well, if a die is your only reference, it's going to be tough. You should have a few mass references. So, is that foam die more like a plastic die, a Hershey's kiss, a quarter, a paper plate, a hairbrush, a full roll of TP? You get the idea. You put something in your hand and think, "This feels heavier than a cell phone but lighter than a grapefruit." And, just by looking at it, you'll know a few things too. So, you've got you foam die in your hand. While it's about the volume of a kiwi fruit, it's a lot less dense, so you use the kiwi fruit's mass as the upper limit and you know you're nowhere close to it. So, you guess much lower.

[bzc11]

Hi, my partner and I got 1st in metric mastery at regionals, but we're worried that we don't know enough metric unit conversions. Is there a good/reliable link for that? (So we can spend our remaining days memorizing). Thanks!!

[Astroknight]

Um..... Wikipedia would be a good place to start.

[hscmom]

Hi, my partner and I got 1st in metric mastery at regionals, but we're worried that we don't know enough metric unit conversions. Is there a good/reliable link for that? (So we can spend our remaining days memorizing). Thanks!!

By "metric unit conversions" do you mean English to metric or metric to metric? I don't think our kids ever had to do English to metric conversions but they found it helpful to know metric-to-metric. They memorized metric prefixes and they also knew the general relationships between units. So, a gram of water is 1 cc or 1 ml (at 20C). And it's good to know that a kilogram is roughly 10 newtons. A newton is about the weight a smaller scientific calculator minus its cover or a new larger size roll of TP and it's a bit more than a pair of safety goggles.

[JustDroobles]

By "metric unit conversions" do you mean English to metric or metric to metric? I don't think our kids ever had to do English to metric conversions but they found it helpful to know metric-to-metric. They memorized metric prefixes and they also knew the general relationships between units. So, a gram of water is 1 cc or 1 ml (at 20C). And it's good to know that a kilogram is roughly 10 newtons. A newton is about the weight a smaller scientific calculator minus its cover or a new larger size roll of TP and it's a bit more than a pair of safety goggles.

It should be metric to metric. Rule 3ciii says they have to convert "metric numbers to a specific different metric unit", and forbids conversions to other systems.

[Unome]

By "metric unit conversions" do you mean English to metric or metric to metric? I don't think our kids ever had to do English to metric conversions but they found it helpful to know metric-to-metric. They memorized metric prefixes and they also knew the general relationships between units. So, a gram of water is 1 cc or 1 ml (at 20C). And it's good to know that a kilogram is roughly 10 newtons. A newton is about the weight a smaller scientific calculator minus its cover or a new larger size roll of TP and it's a bit more than a pair of safety goggles.

It should be metric to metric. Rule 3ciii says they have to convert "metric numbers to a specific different metric unit", and forbids conversions to other systems.

Yeah... the state supervisor made us estimate some of them in inches...