I only attended a few sessions at NCTM-Boston, because I spent a fair amount of time promoting the Lab Gear. I already posted my report on Geoff Krall's strategies to improve the problems we find in standard textbooks. In this post, I'll go over some of the other worthwhile ideas I came across.- Scott Steketee… Continue reading NCTM wrap-up
Blog
About hints
A few days ago, I saw a raging debate on Twitter about hint-giving in math class. It was triggered by a short talk by Michael Pershan, a teacher in NYC. Michael argues that high school teachers need to share good hints with each other, and he proposes some guidelines as to what makes a good… Continue reading About hints
NCTM Report: Adaptation
I'm just back from the NCTM National Meeting in Boston, where I promoted the Lab Gear at the Didax booth, and attended a few sessions.One nice thing about NCTM was the opportunity to connect with friends and colleagues who I don't see often enough. Another is running into fans of my work, which happened with… Continue reading NCTM Report: Adaptation
Logarithms
A young teacher writes:I'm teaching exponential functions and just getting into logs. Everyone tells me that kids tend to struggle with this chapter, so I'd like to try something different than what my school has been doing (just teaching the rules, then practicing over and over again.) Is there a way to introduce logs that… Continue reading Logarithms
Getting Help
In my last post, I described a problem I encountered more than twenty years ago, and my recent attempt at solving it. The problem: Partition the numbers from 1 to 2n into pairs, so that the sum of the numbers in each pair is a perfect square. For what numbers is this possible? I decided… Continue reading Getting Help
I’ve Got a Problem!
Many, many years ago, I saw this problem somewhere:Arrange the whole numbers from 1 to 18 into nine pairs, so that the sum of the numbers in each pair is a perfect square.I liked the problem, and included it in a book I co-authored (Algebra: Themes, Tools, Concepts, following lesson 5.5). In the Teacher's Edition,… Continue reading I’ve Got a Problem!
Pattern Blocks
Geometry of the Parabola
Parabolas are a central topic in high school algebra classes, but, perhaps because of the rigid separation between algebra and geometry classes in the US secondary curriculum, we do not usually treat them as geometric objects. While most teachers are aware of some of the parabola's geometric properties, few of us are familiar with the… Continue reading Geometry of the Parabola
Pie are square
Just in time for π day, I posted an animation that tries to show that the formula for the area of a circle is plausible. Check it out here. It is almost a proof that pie are square!--Henri
Pattern Blocks on Pi Day
I'll be offering a workshop for middle school and high school teachers on March 14 at the American Institute for Mathematics in San Jose. My topic is pattern blocks:<img alt="" height="76" src="data: Pattern blocks are ubiquitous in elementary schools, but they're not commonly seen in middle school or high school. Yet, they do offer plenty of… Continue reading Pattern Blocks on Pi Day
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