
Nelson EducationSchool  
Chapter 6: Addition and Subtraction

Mathematical Processes 
Work meets standard of excellence 
Work meets standard of proficiency 
Work meets acceptable standard 
Work does not yet meet acceptable standard 
Mental Mathematics and Estimation 
• chooses an efficient and effective strategy to estimate a solution
• demonstrates computational fluency that is efficient and flexible 
• chooses a workable and reasonable strategy to estimate a solution
• demonstrates computational fluency that is workable and understood 
• chooses a familiar strategy to estimate a solution, even though it might not be the most appropriate
• demonstrates computational fluency that is routine and familiar 
• chooses a random or inappropriate strategy to estimate a solution
• has difficulty in demonstrating computational fluency and must work through procedures 
Communication 
• provides a precise and insightful explanation of mathematical concepts and/or procedures
• organizes and displays results in effective and clear ways that enhance interpretation 
• provides a clear and logical explanation of mathematical concepts and/or procedures
• organizes and displays results in appropriate and reasonably clear ways that assist interpretation 
• provides a partially clear explanation of mathematical concepts and/or procedures
• organizes and displays results in somewhat appropriate and partially clear ways that make inferring necessary by the reader 
• provides a vague and/or inaccurate explanation of mathematical concepts and/or procedures
• organizes and displays results in haphazard and/or unclear ways that impede interpretation 
Problem Solving 
• develops a thorough plan for solving the problem
• chooses an efficient and effective strategy; may demonstrate creativity and innovation in his/her approach
• verifies solution and accurately determines appropriateness of the response
• draws insightful conclusions based on all available evidence 
• develops a workable plan for solving the problem
• chooses an appropriate and workable strategy
• verifies solution and reasonably determines appropriateness of the response
• draws appropriate conclusions based on relevant evidence 
• develops a basic plan for solving the problem
• chooses a simplistic and/or routine strategy
• attempts to verify solution and determine appropriateness of the response, sometimes correctly, sometimes incorrectly
• draws basic conclusions based on sufficient evidence 
• develops a minimal and/or flawed plan for solving the problem
• chooses an inappropriate or unworkable strategy
• has difficulty verifying solution
• draws faulty conclusions based on insufficient evidence 
