How Many Dinosaurs Do You See?

On Friday, I posed the following question to the class: You are swimming underwater in a lake and see dinosaur feet in the water. You don't want to go to the surface in case they are not friendly dinosaurs. How many dinosaurs are standing in the lake?

Prior to asking them this question, I wanted to tap into their background knowledge to ensure that they knew what dinosaurs were. I read them the story, How Do Dinosaurs Go To School and then showed them various pictures of dinosaurs. While looking at the pictures, I had the kids observe how many legs each dinosaur had, what they looked like, if they looked like a meat eater etc.

I then projected the question onto the screen and had the kids look at the picture to the problem. The picture showed eight dinosaur feet. I then opened it up for discussion. Kids went up one by one to explain how many dinosaurs they thought there were and why. A few of the kids got into a debate about why their answer was the correct one citing "bone structure" and "leg curvatures" to justify their reasoning. :)

The Common Core State Standards for Math focuses on these 8 Standards for Mathematical Practice in addition to specific grade level standards. I encourage you to read them and reflect on what standards for mathematical practice you think were addressed by the kids solving this problem. How many dinosaurs do you think there are? I think there are 8...all posing like ballerinas on one foot. ;)