Chapter 3.2, Problem 10P

David and Ashley want to calculate $\$8.27-\$2.98$ by first calculating $\$8.27-\$3=\$\mathrm{5.27.}$ David says that they must subtract $\$0.02$ from $\$5.27$ , but Ashley says that they must add $\$0.02\text{ to }\$\mathrm{5.27.}$

1. Draw a number line (which need not be perfectly to scale) to help you explain who is right and why. Do not just say which answer is numerically correct; use the number line to help you explain why the answer must be correct.
2. Explain in another way who is right and why.