Primary students (K-2): shapes, number recognition, counting
Intermediate students (3-5): shapes, pattern, area, array model of multiplication, multiplication
This design was drawn by one of my former students during a unit on area. One of the comments on a post-it called this design Batman's Mask and I liked it so...it stuck.
There's a fabulous pattern that emerges when a shape is doubled, tripled, quadrupled in size. And it has to do with square numbers. I wrote a blog post about it years ago, describing the mathematical background so instead of re-writing it all, click here for the information.
"The first one gets 4 times bigger, then 9 times bigger. (Referring to the area.)"
"All of them are the same except that they all are different sizes."
"The length and the width are all different."
"A red rectangle."