## Reflection: Grappling with Complexity PRE-ALGEBRA: Evaluating Expressions - Section 5: Closure

Students did very well with this pre-algebra lesson.  All students were able to evaluate the expressions with a great degree of accuracy.  Because students were able to get the "input-output" idea, I knew that we would be able to proceed into the remainder of the functions unit without any more pre-algebra work.

Despite the work completed in the "do now" portion of the lesson, I did notice that students were still having difficulty with a negative number squared.  When I prompted several students on their thinking, I determined that they had used a calculator and had typed -1^2.  This gave them an answer of -1.  This led to a discussion with the entire class where the students came up with a way to use the calculator to get an accurate answer (-1)^2 (with parenthesis).

The work on the ticket out was encouraging because many students were able to show or describe their thinking on the "Noella" problem.  This is challenging because the question is written in such a way that students could rationalize that both expressions are saying the same thing. However, the students were able to use the order of operations to see that while a fraction line does mean division, writing the expression in these two different ways were not actually equivalent.

(Note: At the beginning of the next class, I asked students to think about how they could re-write the second expression so that it would have the same answer as the first expression.  After they had an opportunity to think, we put up the second student's response so that they could connect to this way of thinking).

Grappling with Complexity: Closure Reflection

# PRE-ALGEBRA: Evaluating Expressions

Unit 1: Functions
Lesson 1 of 18

## Big Idea: Students learn best when they can build their own meaning around content. In this lesson, the students will have a chance to play with numbers while using order of operations to evaluate expressions.

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Standards:
Subject(s):
Math, order of operations, Algebra, evaluate expressions, pre, 9th grade
45 minutes

### James Bialasik

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