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

# Tag: Arithmetic

## 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!

## Proportional Relationships

One good thing about the Common Core middle school standards is the emphasis on proportional relationships, and the fact that they are approached in a multidimensional way. In addition to "set up a proportion and solve it", which is probably the most common way to teach this, the standards propose multiple representations and a variety… Continue reading Proportional Relationships

## Patterns

A correspondent writes:We emphasize the idea that students should approach problems in multiple ways. This has caused me to wonder about patterns. For example:students might conclude that 3^0=1 because of the pattern 3^4=81, 3^3=27, 3^2=9, 3^1=1orwhen the second difference is constant, students will conclude that the function is quadraticorwhen a function is concave up, the… Continue reading Patterns

## Egyptian Fractions

I had a great time at the Julia Robinson Math Festival the weekend before last. Hundreds of kids attended, most of them girls, it seemed to me. The setup: many, many tables; at each table, one or two adult guides, and a math problem that combines access and depth. Students choose a table, and work… Continue reading Egyptian Fractions

## No Three on a Line

In a recent post, I mentioned K-12 Unsolved, the project I'm involved in that aims to publicize 13 unsolved math problems, in the hope that an appropriate version of each problem will find its way into K-12 classrooms. One problem we looked at was posed by Henry Dudeney in 1917. Here is the problem: Consider… Continue reading No Three on a Line

## Geoboards and Dot Paper

If you are familiar with my curricular creations, you know that I often use the geoboard as a microworld to introduce interesting problems and important concepts. This is in line with my call for a tool-rich pedagogy. (A geoboard is a square lattice pegboard on which students use rubber bands to create and investigate geometric… Continue reading Geoboards and Dot Paper

## Crowd-Sourcing

Well, not much of a crowd, because not many people read this blog. Still... I created four worksheets of sorts, each one consisting of a short title and images of a dozen circles. Each circle is divided pizza-like into slices, as in the example above. The four titles: Angles, Fractions, Time, and Percents/Money. Here is… Continue reading Crowd-Sourcing

## March 19 in Palo Alto

Once again, I will be presenting function diagrams to a math circle for teachers, this time for the American Institute of Mathematics Circle for Teachers. This will happen on March 19, at 340 Portage Ave. Palo Alto, from 5:00 to 8:00 p.m. There is no charge, and in fact a free dinner is provided. Here… Continue reading March 19 in Palo Alto