This week, as part of series of posts on “First Steps” for bringing math off the page and into our students’ bodies, we’ll continue investigating what familiar math concepts look like in the wild. In this post I’ll be looking at the idea of units and part-whole relationships as they present themselves in daily life.
One of the places we can find units and other examples of parts and wholes off the page is in classic children’s pattern- and rhythm-based play like jump rope or clapping rhymes, like in this video of spontaneous game play at a summer program I did a while back. One thing I know for certain: when there is tape on the floor where there once was none, interesting things always happen!
The body can be harnessed as informal thinking tool on the playground and also more formally in math class, and is well suited to investigations of part-whole relationships and is at the core of our math-dance making in Math in Your Feet.
Types of Units: Breakfast Edition
A unit is a single quantity regarded as a whole.
Composed units begin with a single thing which we assemble with others of these single things to make a larger unit: the assemblage of units becomes a single whole. For example, in your refrigerator you likely have a carton of eggs. The original unit is an egg. The composed unit is 12 of these: a dozen eggs.
A loaf of bread however, is not a composed unit because we don’t make the loaf out of slices. Instead, we start with a loaf and partition it into smaller units…and then toast it up to go with our egg.
Also consider a natural unit which refers to a composed unit that has to be the size that it is, like a pair of shoes or a pair of mittens.
Here are a couple quick videos of original Math in Your Feet patterns created by the dancers themselves! The base unit is four beats, and the two teams combined their patterns to create a longer pattern composed of two four-beat patterns.
Here’s another fun 8-beat pattern which, I’m pretty sure, Max created. We were at Twitter Math Camp this Summer and we were setting up for some after-hours math-dancing in the Blue Tape Lounge. You can read more about our evening here.
Building a flexible understanding of part-whole includes understanding the myriad ways this idea presents itself in a variety of contexts. This includes the familiar operations of addition/subtraction, multiplication/division and measurement (which you can experience both on and off the page) but Sarama and Clements (2009) also include, among other things, unitizing, grouping, partitioning, and composing as operations as well, leaving the door wide open to pretty much everything we do while we are thinking mathematically.
The idea also shows up in some unexpected places, like the sidewalk…or the sky…or during breakfast…
— Brian Bushart (@bstockus) July 28, 2015
— Paula Beardell Krieg (@PaulaKrieg) July 23, 2015
Here is my all-time favorite piece of math art, probably because it’s math that moves! The video starts by partitioning a humble equilateral triangle. Math off the page sometimes moves quickly, but I bet you can follow the different relationships that develop as different forms are composed or partitioned.
What every-day examples of units or part/whole relationships can you find off the page this week? Share your answers with us at the Math on the Move book group or, if you’re on Twitter check in and/or post to the #unitchat hashtag. Hope to see you there!
Malke Rosenfeld is a dance teaching artist, author, editor, math explorer, and presenter whose interests focus on the learning that happens at the intersection of math and the moving body. She delights in creating rich environments in which children and adults can explore, make, play, and talk math based on their own questions and inclinations. Join Malke and other educators on Facebook as we build a growing community of practice around whole-body math learning.