All posts by Daniel Scher
Zooming Integers: Magnifying the Number Line
In my prior post, I presented a "zooming" number line model that allowed students to estimate the location of a point along a number line and then repeatedly magnify that portion of the number line to obtain ever-finer estimates, accurate to tenths, hundredths, thousandths, and beyond.
In a sense I got ahead of myself because I … Continue Reading ››
Zooming in on Place Value
One of the aspects I like best about Dynamic Geometry software like Web Sketchpad is its ability to illustrate concepts that cannot effectively be represented with static media. Take, for example, a number line that we draw on a white board. Showing the number … Continue Reading ››
Exploring Triangle Area with Custom-Built Tools
With Web Sketchpad, it's easy to craft tools that are tailor made for the task at hand. I was reminded of this flexibility several weeks ago when creating an interactive model for the elementary curriculum Everyday Mathematics.
My goal was to design a lesson focusing on the triangle area formula, A … Continue Reading ››
Around and Around: Investigating Multiples
In my prior posts ( When Factoring Gets Personal, Open the Safe, and Reasoning with Multiples to Find the Mystery Number), I’ve given examples of how learning about multiples and factors … Continue Reading ››
Constructing Equal-Area Triangles
The origins of this week's Web Sketchpad model date back to the Connected Geometry curriculum from the mid 1990s. I was one of the co-authors of the curriculum, working at Education Development Center with a wonderful team of math educators (Al Cuoco, … Continue Reading ››
Reflecting on the Annual NCTM Meeting
This Thursday, Scott Steketee and I will be presenting two sessions at the NCTM 2015 Annual Meting in Boston:
Functions as Dances: Experience Variation and Relative Rate of Change
Session 52 on Thursday, April 16, 2015: 8:00 AM-9:15 AM in 157 B/C (BCEC)
How better to explore rate of change than as independent and … Continue Reading ››
Solving Simultaneous Equations with Common Sense
Simultaneous equations belong in elementary-school mathematics curricula. That's been my mantra for many years, and I want to examine it now in the context of an interactive Web Sketchpad activity.
When I say that elementary-age students should encounter simultaneous equations, I don't mean that they should be instructed in the standard algebraic procedure for solving pairs of equations … Continue Reading ››
Drawing an Ellipse with Pins and String
In my prior blog posts, I've described how to construct ellipses using linkages, concentric circles, congruent triangles, and tangent circles. These are all great methods, but I think I got ahead of myself: … Continue Reading ››
Moving Beyond Formulas When Investigating Triangle Area
For the past year, my blogging partner Scott and I have worked with the team of Everyday Mathematics to build interactive Web Sketchpad models for their forthcoming new edition. It's been fun for both of us to find ways to insert dynamic mathematics into their K–6 curriculum. Last year, I … Continue Reading ››