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  • Writer's pictureJoanne Jacobs

If you have to think about 3x = 18 . . .


Thinking about everything is hard, writes Greg Ashman, author of Cognitive Load Theory, on Filling the Pail. It exhausts students' extremely limited working memory. What teachers want is for to activate a web of knowledge -- a "schema" -- in long-term memory to solve problems.


Alfred North Whitehead, a mathematician and philosopher, observed:

“It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them. Operations of thought are like cavalry charges in a battle — they are strictly limited in number, they require fresh horses, and must only be made at decisive moments.”

Ashman critiques Peter Liljedahl’s book, Building Thinking Classrooms in Mathematics. The author wants students to figure out how to solve problems themselves without "mimicking" the teacher's explanation.


Liljedahl’s ideas are "a recipe for confused and overloaded students," not the basis of a sustainable teaching plan, Ashman concludes. "We would quickly run out of fresh horses."


Reformers assert that they're improving math learning in ways that can't be measured, writes Ashman. He's dubious. He also doesn't believe in "math zombies" who don't understand math but can solve all the problems.


Some students "are not inclined to solve a problem three different ways or witter on in English about how they did it or whatever else we have prioritised over actual mathematics," writes Ashman. Their ability to ace tests is explained away as "rote memorization" of procedures. "When deployed to explain away the success of students in the Far East on international assessments such as PISA and TIMSS, this takes on a frankly racist tone."


It is not up to teachers to prove that a new approach is unlikely to work, writes Ashman. The math ed guru bears the burden of proof.


Natalie Wexler explains how cognitive-load theory applies to teaching reading on Forbes. It's an excellent explanation of why people need to move information from short-term to long-term memory, organized in a way that enables them to retrieve it.



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5 Comments


Steve Sherman
Steve Sherman
Mar 22, 2023

I was a volunteer math teacher for a job training certification class through the YMCA - the people in the class could barely add and subtract much less do algebra. It really makes you wonder how these poor people get thru life. But equally dispiriting was whether the people could count to 5 on their fingers or add 2+2 they all got the certificate at the little going away party.

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Guest
Mar 22, 2023

That method of teaching math has to have been proposed by someone who hates math and mathematical reasoning. The people who are good at algebra are the people who looking at a problem and quickly recognize what kind of problem it is. The people who suffer through Algebra never get the recognition ability down to being usable.

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Guest
Mar 22, 2023

3x = 18 is 6...


Rote memorization is important when working with basic numbers and money... I do this when I use a drive thru to figure out what my change should be.


The issue isn't as big of a problem in grocery stores these days with self checkout

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Guest
Mar 21, 2023

Can I get an Amen!

--mrmillermathteacher

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lady_lessa
Mar 22, 2023
Replying to

AMEN

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