Worked examples have been found to be effective tools in reducing cognitive load and supporting learning. Erroneous examples are worked examples that include incorrect steps and are intended to help students learn how to identify important principles and errors to avoid. The current study examines whether using erroneous examples in an online intelligent tutoring system can help middle-school children learn decimals beyond simple problem solving with feedback. Results showed that although students did not differ between the two conditions on an immediate posttest, students in the erroneous examples group performed better on a delayed posttest. This suggests that working with errors, and thus processing the decimal problems at a deeper level, helped students retain more about decimals and build upon that understanding over time.