I directed Natalie to study the examples in the text on calculating the increase or decrease in percents. I gave her six problems to work on independently and left her to go to the teachers' room. Near the end of the session, she told me she had finished the problems. I checked them and found that she had the right process in some of the problems but had failed to divide correctly. She also divided by the wrong number in the two problems where there was a decrease in value. I told her that we would re-visit these problems and more like it the next class session. There was no assignment by Natalie's request.