teaching measurement conversions

How about something visual? Hand out to each child a strip of paper the size of a ruler. Then tell each to cut it up into as many nearly equal sized pieces as they want. Then you can show them that (for example) 6 Sally-units equals 12 Tommy-units equals 2 Fred-units. Then you can go on to the fractions to come up with how many Tommy-units go into 1 Sally-unit.

Kay

When I did this w/an inclusion class, kids invented a new unit of measure—which, of course, T. Jefferson & friends did with American Standard measure. They could have used metric with their French buddies.

Do lots of comparisons of the new unit with American Standard. Then, do a story about the metric metric measurement inventors and what was used before that. Then have kids do lots of measuring to compare the two.

After the concrete has absolutely gelled to the max, *then* introduce the algorithm for conversions. Try to hook to real life. Not easy, unless you’re planning a trip to Mexico.

I think metric is way easier and love teaching it.

Two questions here: (a) concept of measurement, and (b) conversions.

The concept has to be learned and practiced for a long, long time before the conversions make sense. If you try to teach them together you will get nowhere (sounds like you already proved that.)

Hate to disagree with Susan L, but the American standard system was adopted, unfortunately, pretty much whole hog from the British. Metric was invented during the time of Napoleon, a few decades later, and alas the Americans didn’t adopt it at the time.

My daughter learned metric first in Quebec, had to try to catch up with American in Grade 4 when we came down to New Hampshire (and she’s still sketchy on some details but doesn’t need them) and laughed herself to hysterics when her classmates in junior high and high school moaned about how “hard” metric is. Same as I’ve said about reading and writing and speaking a language and swimming, whatever you learn first, no matter how bizarre, always seems “right” to you, which is one reason to be very insistent about directionality in learning handwriting, why kids who learn phonics first have far fewer reading problems, why metric will never be accepted until the elementary teachers *have* to learn and teach it to a new generation, and otherwise never practice a mistake.

I’ve heard the suggestion of inventing your own units many times before; the first question with this is how much time you have. It’s going to consume a lot of energy and time to get across the idea of a unit, have everybody use their own, and compare everybody’s. I could see it taking a week or two in a regular class and a lot more in special ed. If you can spend the time, have fun. The second question is whether you have any one-way learners, the kind of kid whom you have to drag kicking and screaming (metaphorically at least most of the time) through every new idea, and who then takes the new idea to heart and fights you bitterly over against any further change. If you have any of these, you might think twice over inventing your own measure first (one pitched battle) and then accepting somebody else’s (an all-out war.)

I’ve taught measurement in primary, and we taught simply centimeters for the entire first grade. We mentioned meters once or twice but never required anything more than vague recognition, never conversion; that comes with division and multiplication no earlier than the end of Grade 2, so the kids had at least a year of just measuring with one unit. This makes sense to get the concept down. The kids measured pencils, erasers, books, their desks, and their heights, all counting in centimeters. You could do the same with inches.

I’m sure you are right about the U.S. adopting English measurement. One of the Am Hist books I’ve read, though, discusses Jefferson & Franklin’s work with the French philosophers who proposed the metric system about the time the U.S. was truly up & running (early 1800’s). I thought that to be an interesting story to “recount” quickly to kids to help them understand that this is truly an arbitrary process. I would then “bring out” *my* standard of measure: “the merkle” and have them decide what is good & not good about it.

I’m not a primary grades teacher, as you might guess…

I’m a long-term sub teaching high school special ed. I’ve read your suggestions and they’re all good, but I have a very specific problem. I’m teaching 9th grade science, and while all my students were a little intimidated by the metric system, I have one student who simply cannot read a ruler, whether it’s metric, English, or a triple beam balance. I’ve tried having her look at the big units first and then the smaller ones, but she seems to be completely unable to count the units on her own and write them down, much less add and subtract them. Help!

When you say she can’t do it at all, the question is, how bad?
I’m presuming she can read and write numbers, or you’d be asking about that — or can she? This is a serious question — sometimes one apparent problem shows up a much deeper disability. Have her read a couple of numbers out loud to you, and check out her addition and subtraction. If she can’t do that, well, you know where to start.
Ok, if she can read and write numbers and add and subtract, then can she read the whole numbers on a simple number line?
Can she read the whole numbers on a ruler?
OK, then you can start by having her measure things to the nearest centimeter.
You will have to work for some time about lining up the zero.
Do lots and lots of practice on that before you try to do parts.

I spoke with her math teacher and this student is just beginning to understand how to use a number line to do simple subtraction. Her IEP shows no indication of her reading level so she’s being assessed some time next week. We’re reading the text aloud in class (though she has not taken a turn) and she was able to give definitions on a quiz, so obviously,she has some command of language.

Darling high school students often enjoy pretending. I’d be checking this one out. Is she EMH? Autistic? (Forgive me if I missed something earlier in the thread…I’m answering from email.)

OK, if she is still just starting to use a number line, fancy work with rulers is just out of her league. You can try to get a primary ruler for her — they have just the whole numbers and no other marks. You can show her how this is her own personal number line, which is a nice thing to have, and start teaching her to line up the zero on one side and count how many inches or centimeters, to the nearest whole unit, to the other side of an object. That’s as far as she will go until she has some more number skills.

Sue,

My son reads great but can’t do math using the numbers chart. He can use manipulatives and the cuisenaire rods are great. He understands what the numbers are, can skip count and can relate that to multiplication, can then demonstrate the skip counting with the cuisenaire rods, for example if this block is 3 what are 3 do 3 of these blocks equal.
He would also get confused when subtraction and addition math facts were presented on the same page. He would not look closely enough and add when he was supposed to subtract.

My son tested very low on the bender. He has visual motor deficits.

He has actually improved greatly with many visual/motor activities since doing visual perception exercises and interactive metronome. He no longer gets confused by addtion and subtraction problems on the same page.

You have reminded me to try the numbers chart again.
You may want to have a look at this childs’ tests and see if their is any indictation of a visual processing or visual/ motor problem.