Two Digits with Icons
This is the first in a sequence of lessons
on subtraction for one of my students. At the time that the recording was made she was starting
the 3rd Grade. I did not teach her how to solve the
problems that she is working on. The reasoning that she uses is entirely her own.
What To Look For In This Video
- In the first 2 problems her overall logical reasoning is sound, but she makes some relatively minor, easily corrected, mistakes.
- It is clear from her work on the next 2 problems that she has perfected her logic - she does both problems correctly, using the same method each time.
- Notice my emphasis with her on her reasoning. I am more interested in her logic, and in her ability to articulate her logic, than I am in her answer.
- Also notice that the reasoning of her method is not at all like the standard algorithm that is taught in school. (In particular, she works on the tens first and doesn't "borrow" to make a teen.)
- She did all of the problems that followed using the same logic.