Substitution (…and Continued Fractions)

Sam Shah, with a great mechanism for substituting an expression with an equivalent variable: use a note card with the expression on one side and the variable on the other.

I emphasized that that card itself represented the value of that fraction. The front and back are both different ways to express the same (unknown) quantity we were looking for.

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THAT FLIP IS THE COOLEST THING EVER FOR A MATH TEACHER. That flip was the single thing that made me want to blog about this.

Love it.