Well, I bombed a lesson in geometry on geometric mean today. I went way too fast through the different similar triangles, tomorrow is a new day and another try at it. It is my first time through geometry so I am not as prepared in how to explain certain concepts. Whereas this is my third year through this portion of the algebra curriculum.
Last year I asked them which calculator is correct. This year I didn’t say anything and let them ask the questions.
We are working on exponents and there have been some good discussions over order of operations since T.I. calculators say -3² = -9 and iPhones say -3² = 9. A good extension on this opener is to ask what solution each calculator would spit out for another expression.
*I don’t remember where this image came from… if you have seen it before let me know and will give out some credit.