MoCA Calculation Skills 3 — Questions and Answers
Question 1: How many individual subtraction attempts are made in the MoCA serial 7 task?
- 3 attempts
- 4 attempts
- 5 attempts (Correct answer)
- 7 attempts
Correct answer: 5 attempts
The examiner asks for 5 consecutive subtractions of 7 starting from 100 (93, 86, 79, 72, 65), giving 5 individual attempts to score.
Question 2: When evaluating calculation ability with the MoCA serial 7 task, clinicians should be cautious interpreting low scores in patients who:
- Are over 65 years old
- Have limited formal education or low numeracy backgrounds (Correct answer)
- Are native English speakers
- Have hearing impairments
Correct answer: Have limited formal education or low numeracy backgrounds
Education and cultural background strongly influence performance on arithmetic tasks. Low serial 7 scores in individuals with limited formal education may not reflect cognitive impairment.
Question 3: A patient answers: 93, 86, 79, 72, 65. What is their serial 7 score?
- 5 points
- 3 points (Correct answer)
- 4 points
- 2 points
Correct answer: 3 points
All five answers are correct (100-7=93, 93-7=86, 86-7=79, 79-7=72, 72-7=65). Five correct answers earns the maximum score of 3 points.
Question 4: The MoCA serial 7 task is classified under which cognitive domain on the score sheet?
- Executive function
- Memory
- Attention (Correct answer)
- Language
Correct answer: Attention
Serial 7 subtraction is placed within the Attention domain on the MoCA score sheet, alongside digit span and letter vigilance.
Question 5: What cognitive processes are simultaneously engaged during serial 7 subtraction?
- Only arithmetic recall
- Only working memory
- Arithmetic, working memory, sustained attention, and mental flexibility (Correct answer)
- Visuospatial processing and naming
Correct answer: Arithmetic, working memory, sustained attention, and mental flexibility
Performing serial 7s requires arithmetic knowledge, working memory to hold the running total, sustained attention to stay on task, and mental flexibility — making it a rich multi-domain task.
Question 6: In MoCA scoring, a patient who correctly subtracts 7 only once (getting 93 right, then failing) earns:
- 0 points
- 1 point (Correct answer)
- 2 points
- 3 points
Correct answer: 1 point
Per MoCA scoring rules, exactly 1 correct subtraction earns 1 point. Errors on subsequent attempts do not negate the one correct response.
MoCA Calculation Skills 3
How many individual subtraction attempts are made in the MoCA serial 7 task?