Unequal understanding
Aug. 12th, 2010 07:31 amAmerican students tend to misunderstand the meaning of the equal sign far more than international counterparts.
The article is decent, and the study says exactly what I'd expect it to say. The idea of balancing numbers on both sides of the equal sign is crucial to algebra, but most students taught procedurally understand the equal sign to mean, "This is where I put my answer."
However, the article attributes the problem to poor textbooks. While this is probably a factor, I'd call it correlation rather than causation, because over-reliance on textbooks for mathematics instruction is symptomatic of the poor teaching that leads to the misunderstanding of the equal sign. Studies have shown that teachers who teach from the textbook most of the time generally rely on the textbook to lay out their plans for them. They'll spend exactly as much time on a topic as the textbook will - even if their students don't yet understand. Any mathematical concept that the textbook is unclear on, the students will be unclear on too, because the teacher is unlikely to address it outside the framework of the textbook.
Solution: get kids as young as grade one working on addition and subtraction sentences that involve balancing equations: 4+2=9- ___, for example. For primary classrooms, have a graphic of a teeter-totter with the equal sign on the fulcrum, and make it clear that the idea is to balance the teeter-totter in the middle. Do this all the way through the primary grades with increasingly complex problems and manipulatives.
By grade five, kids are ready to be introduced to the idea of a variable to take the place of the blank; they're also ready to solve problems by making tables of values that rely on one thing being equal to another: "A spider travels 19 cm every second. How long will it take her to travel the perimeter of a room that is 3m x4m?" One logical starting point is 1 second = 19cm, and the table of values can be built up from there, provided the students know they have to keep counting the number of nineteens in order to balance the equation.
Thanks to
ankh_f_n_khonsu for the link.
The article is decent, and the study says exactly what I'd expect it to say. The idea of balancing numbers on both sides of the equal sign is crucial to algebra, but most students taught procedurally understand the equal sign to mean, "This is where I put my answer."
However, the article attributes the problem to poor textbooks. While this is probably a factor, I'd call it correlation rather than causation, because over-reliance on textbooks for mathematics instruction is symptomatic of the poor teaching that leads to the misunderstanding of the equal sign. Studies have shown that teachers who teach from the textbook most of the time generally rely on the textbook to lay out their plans for them. They'll spend exactly as much time on a topic as the textbook will - even if their students don't yet understand. Any mathematical concept that the textbook is unclear on, the students will be unclear on too, because the teacher is unlikely to address it outside the framework of the textbook.
Solution: get kids as young as grade one working on addition and subtraction sentences that involve balancing equations: 4+2=9- ___, for example. For primary classrooms, have a graphic of a teeter-totter with the equal sign on the fulcrum, and make it clear that the idea is to balance the teeter-totter in the middle. Do this all the way through the primary grades with increasingly complex problems and manipulatives.
By grade five, kids are ready to be introduced to the idea of a variable to take the place of the blank; they're also ready to solve problems by making tables of values that rely on one thing being equal to another: "A spider travels 19 cm every second. How long will it take her to travel the perimeter of a room that is 3m x4m?" One logical starting point is 1 second = 19cm, and the table of values can be built up from there, provided the students know they have to keep counting the number of nineteens in order to balance the equation.
Thanks to
(no subject)
Date: 2010-08-12 12:03 pm (UTC)(no subject)
Date: 2010-08-12 12:09 pm (UTC)Elizabeth is quite capable of doing the types of problems I mentioned, too. Her teacher gave her some - I loved her teacher when it came to math, she was excellent - and I gave her some more.
When he thinks he's discovered something new like that, don't deflate the bubble. He constructed a piece of knowledge that was new for him, and he should be proud of that. The fact that others have constructed the same knowledge doesn't make his accomplishment any less valid, because everyone has to come to understanding by constructing knowledge exactly the way he did.
(no subject)
Date: 2010-08-12 12:28 pm (UTC)Amen to that! I always know, upon meeting a new teacher, how bad they are when one of the first things they ask me is what textbook our district uses for a class. Curriculum mapping doesn't always solve the problem either, because many teachers who volunteer to do the mapping (including our department head!) just go through the book and match book topics to the state standards. *headdesk*
What are the odds you could come to Massachusetts and run PD for elementary teachers around here?
(no subject)
Date: 2010-08-12 12:36 pm (UTC)Suggest they get their hands on a couple of Marilyn Burns books, or John van der Walle, or both, and base their programs off of those instead of a textbook. They'll get further.
(no subject)
Date: 2010-08-12 01:21 pm (UTC)(no subject)
Date: 2010-08-12 03:58 pm (UTC)(no subject)
Date: 2010-08-12 04:17 pm (UTC)(no subject)
Date: 2010-08-13 01:26 am (UTC)For my part, now that you've made me consider how I comprehend it, my brain reads the equals sign almost different in those situations. I obviously know what it means in either case, but I feel like it's a different symbol. In my head.
I'm not making much sense. But I can do math, I promise!
(no subject)
Date: 2010-08-13 08:14 am (UTC)