## Reflection: Checks for Understanding Area Battles - Section 3: Comparing Monsters

There is a difference between completing the computations in math and understanding why you are doing what you are doing.

This is very evident with comparison problems. Comparison, by nature is either a subtraction or a missing addend problem. Some students started to compare their monsters by adding the area  of the first to the area of the second. I had done an earlier demonstration as I talked, where I showed the bigger number (the larger monster) and the smaller number (the smaller monster), and I used my hands to show that we can't have something bigger than the big monster if we are comparing it to the small monster. Students nodded their heads as if they understood.

When they went to work in their groups, a number of students immediately started to add the 2 numbers. Were they capable of adding or subtracting the numbers ? Yes, the computation, while not super easy, was possible for everyone in the room, but the understanding of what a comparison means, and how to use that understanding to choose the correct operation, was lacking.

I will go back to block comparisons to reconnect students to the understanding of what a comparison means. A linear comparison is easier for students to see so I demonstrate with the block towers to show that a comparison is not adding one tower to the other, but seeing how much taller or bigger one is than the other.

What Is Comparison?
Checks for Understanding: What Is Comparison?

# Area Battles

Unit 13: Area, Perimeter and More Measurement
Lesson 6 of 6

## Big Idea: Student-made monsters on grid paper are a great way to stimulate comparison problem-solving.

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### Beth McKenna

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