The purposes of error analysis are to (1) identify the patterns of errors or mistakes that students make in their work, (2) understand why students make the errors, and (3) provide targeted instruction to correct the errors. When conducting an error analysis, the teacher checks the student’s mathematics problems and categorizes the errors. The following is a list of errors that students commonly make in various mathematical areas (Ashlock, 1986; Tindal & Marston, 1990).

Addition and Subtraction

  • Lack of understanding of regrouping
  • Confusion of 1s and 10s in carrying and writing
  • Forgetting to carry 10s and 100s.
  • Forgetting to regroup when subtracting 10s and 100s.
  • Regrouping when it is not required.
  • Incorrect operation (the student subtracts instead of adding or vice versa).
  • Lack of knowledge of basic number facts.

Multiplication and Division

  • Forgetting to carry in multiplication.
  • Carrying before multiplying.
  • Ignoring place value in division.
  • Recording the answer from left to right in multiplication.
  • Lack of alignment of work in columns.
  • Lack of knowledge of basic number facts.


  • Incorrect cancellation.
  • Failure to reduce to lowest common denominator.
  • Ignoring the remainder.
  • Incorrect conversion of mixed numbers to fractions.

Word Problems

  • Difficulty in reading.
  • Inability to relate to context of problem.
  • Inability to understand the language and vocabulary of the problem.
  • Difficulty in identifying the relevant and the irrelevant information.
  • Difficulty in identifying the number of steps required to solve the problem.
  • Trouble in doing mathematical operations (addition, subtraction, multiplication, division).