Chapter 3.2, Problem 9P

To calculate $201-88,$ a student writes the following equations:

  $88+2=90+10=100+100=200+1=201$

  $2+10=12+100=112+1=113$

Although the student has a good idea for solving the problem, his equations are not correct. In words, describe the student’s solution strategy and explain why it makes sense; then write correct equations that correspond to this solution strategy.