## Using an Elevator to Evaluate Signed Number Expressions

Using the idea of an elevator moving up and down, students will be given a small set of rules to add and subtract signed integers.

The idea behind the method of adding and subtracting signed integers offered in these lesson is that the number of rules that students have to memorize and the amount of understanding are minimal.

### Math Content

Adding and subtracting of signed integers.

### In the Classroom

"It's a nice introduction to adding and subtracting simple signed number problems. Students got it, and it was more interesting than a basic number line." -Jaime Kearney, Math Department Chair (MCI; Pittsfield, ME)

### Elevator Arithmetic

Students will use vertical movement of an elevator to evaluate signed number expressions.

The idea behind the method of adding and subtracting signed integers offered in this lesson and the next is that the number of rules that students have to *memorize* and the amount of *understanding* are minimal, while the underlying concepts are not trivialized.