Construct a Building: Modeling Multiplication with Arrays

When Scott Steketee and I developed activities for the Dynamic Number project, we thought about ways that dynamic array models could help children to conceptualize multiplication.

Rather than presenting children with arrays that were fully formed, we thought it would be instructive for them to build these arrays themselves. That design goal led to the … Continue Reading ››

Visual Models for Adding and Subtracting Fractions

How can we visualize the process of adding or subtracting fractions with unlike denominators? The Web Sketchpad model below (and here)  offers tools for representing fraction addition and subtraction on a number line as well as a parameter (called "divisions") that allows you to find a like denominator through visual inspection rather than calculation.

[iframe … Continue Reading ››

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