Using
Visual Representations to Find New Patterns
This
past week we started practicing the thinking habits that mathematicians use.
The students were given this problem:
The Painted Cube
A 3 x 3 x 3 cube is
dipped into paint. How many of the 1 x 1 x 1 cubes
would have 3 sides
painted? 2 sides painted? 1 side painted? 0 sides painted?
What if the cube was a 4
x 4 x 4? A 5 x 5 x 5?
By the end of the first session most students were able to come
up with the number of cubes for each of
the categories, and some students had creative ways to track how many cubes would
have 3 sides, 2 sides, 1 side or 0 sides painted. Most could find some patterns, but for some of the numbers the patterns were challenging to discern.
The next day, we talked about creating and recording visual representations and connecting them to numerical or symbolic representations. We created these visuals in order to look for patterns that would help us come up with Generalizations for a 4 x 4 x 4, a 5 x 5 x 5 or a cube even larger. The challenge was to come up with the patterns that would help students to determine how many cubes would fit in each of the categories without building and counting cubes.
Different teams came up with some helpful visual representations that helped everyone continue looking for patterns.
Student Voices Describing Patterns
After creating more systematic visual representations, students were able to describe and Justify the patterns they were seeing and how they would grow to larger cubes. Listen to Emily and Jonathan
share their arguments.
Listen to Matthew as he describes an equation he sees for any size cubed. If y = a side length, then (y-2) x 12 will calculate all the cubes that have only 2 sides painted.
Ask your child to share some pattern they saw in the cube patterns. I have included a visual representation to help them share their thinking.