Not my best lesson.
Oct. 13th, 2009 05:10 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
velvetpageOn Friday, I showed the kids number lines that went from 0 to 1, divided into tenths.
Today, they had to use a number line from 3 to 5, and show 4.25 on it.
There were some kids who made a number line, divided the spaces between the whole numbers into quarters, and could justify 4.25 as the first quarter after four - perfectly acceptable. Others did it the way I'd been expecting, drawing a number line with ten divisions between each whole number and putting 4.25 halfway between 4.2 and 4.3. Also perfectly acceptable, of course.
The problem was with the kids who drew a number line with ten divisions and put 3 at one end, 4 in the middle, and 5 at the other end, leaving them with five divisions between each whole number. I should have gotten those kids together and asked questions to get them to clarify - maybe have them label the divisions so I could see if they actually labelled them correctly (0.2, 0.4, etc.) or some other way, incorrectly. If they labelled them incorrectly, I could then have gotten the kids to think through the concept of the divisions and compare them to the other number lines they've done, until they realized for themselves that it didn't look right. If they labelled them correctly and figured out that 4.25 had to be one quarter of the way between 4.2 and 4.4, then there would be no problem - that's another perfectly adequate solution.
Instead, I handled it in precisely the wrong way - I told them they were wrong and needed to think it through again, which didn't give them any way of doing that and didn't really establish what they understood or misunderstood of the question.
Um, oops. I'm chalking it up to post-long-weekend brain fuzz.
Thursday's lesson will be better. The problem: As a class, we're going to send a parcel to a school in Afghanistan with school supplies on it. Problem is that Canada Post charges a lot more to ship parcels over 50 kg, so we need to figure out how best to organize our school supplies to come as close to the weight limit as possible without going over. (There follows a list of simple school supplies, in sets of ten or twelve each, which we will weigh as a class using a scale borrowed from the science room, accurate to hundredths of a kilogram.) Given these weights, make a proposal for what we should include in our care package to the school in Afghanistan.
If they're really interested, there is a program like that through Plan International and another through the Canadian Military which I'm quite happy to look up - though without the weight limit, which is artificial to give them an adding problem. We'll get half a dozen problem-solving strategies out of it and get to discuss a world issues topic as well. It's win-win.
Today, they had to use a number line from 3 to 5, and show 4.25 on it.
There were some kids who made a number line, divided the spaces between the whole numbers into quarters, and could justify 4.25 as the first quarter after four - perfectly acceptable. Others did it the way I'd been expecting, drawing a number line with ten divisions between each whole number and putting 4.25 halfway between 4.2 and 4.3. Also perfectly acceptable, of course.
The problem was with the kids who drew a number line with ten divisions and put 3 at one end, 4 in the middle, and 5 at the other end, leaving them with five divisions between each whole number. I should have gotten those kids together and asked questions to get them to clarify - maybe have them label the divisions so I could see if they actually labelled them correctly (0.2, 0.4, etc.) or some other way, incorrectly. If they labelled them incorrectly, I could then have gotten the kids to think through the concept of the divisions and compare them to the other number lines they've done, until they realized for themselves that it didn't look right. If they labelled them correctly and figured out that 4.25 had to be one quarter of the way between 4.2 and 4.4, then there would be no problem - that's another perfectly adequate solution.
Instead, I handled it in precisely the wrong way - I told them they were wrong and needed to think it through again, which didn't give them any way of doing that and didn't really establish what they understood or misunderstood of the question.
Um, oops. I'm chalking it up to post-long-weekend brain fuzz.
Thursday's lesson will be better. The problem: As a class, we're going to send a parcel to a school in Afghanistan with school supplies on it. Problem is that Canada Post charges a lot more to ship parcels over 50 kg, so we need to figure out how best to organize our school supplies to come as close to the weight limit as possible without going over. (There follows a list of simple school supplies, in sets of ten or twelve each, which we will weigh as a class using a scale borrowed from the science room, accurate to hundredths of a kilogram.) Given these weights, make a proposal for what we should include in our care package to the school in Afghanistan.
If they're really interested, there is a program like that through Plan International and another through the Canadian Military which I'm quite happy to look up - though without the weight limit, which is artificial to give them an adding problem. We'll get half a dozen problem-solving strategies out of it and get to discuss a world issues topic as well. It's win-win.