Earlier in the section, there was a warning about adding and subtracting in columns when working with negative numbers. We are going to explore the challenges that arise in this setting in order to more fully understand the challenges that arise from working in columns.
Below a possible first step (ones column) of the calculation \(-53 + 27\) when performed using columns:
Identify the error that has already taken place in this calculation.
3.
There is a "rule" that can be used for doing this calculation in columns. To calculate \(-a + b\) (where and are positive numbers).
Step 1: Identify the larger number.
Step 2: Perform the calculation "larger minus smaller."
Step 3: Give your result the same sign as the larger number in the original problem.
Apply this "rule" to the calculation \(-53 + 27\text{.}\) Explain how this "rule" is a more complicated expression of the number line calculation.
