MoCA Calculation Skills 3 — Questions and Answers
Question 1: The MoCA serial 7s subtraction task is primarily designed to assess which cognitive domain?
- Language fluency
- Attention and working memory (Correct answer)
- Visuospatial ability
- Delayed recall
Correct answer: Attention and working memory
The serial 7s task targets attention and working memory by requiring sustained mental calculation.
Question 2: A patient scores 1 out of 3 on the MoCA serial 7s. How many of the five subtractions did the patient answer correctly?
- Exactly 1 (Correct answer)
- Exactly 2 or 3
- Exactly 4 or 5
- None
Correct answer: Exactly 1
MoCA scoring: 1 correct = 1 point, 2–3 correct = 2 points, 4–5 correct = 3 points.
Question 3: What is the correct result of subtracting 7 from 79?
- 73
- 71
- 72 (Correct answer)
- 74
Correct answer: 72
79 minus 7 equals 72, which is the fourth step in the serial 7s sequence from 100.
Question 4: In the MoCA serial 7s task, the examiner says 'subtract 7' five times starting at 100. What is the fifth (final) expected answer?
- 58
- 65 (Correct answer)
- 63
- 60
Correct answer: 65
The sequence is 93, 86, 79, 72, 65; the fifth subtraction results in 65.
Question 5: Which condition would most directly impair a patient's ability to complete the MoCA serial 7s task?
- Peripheral neuropathy
- Working memory impairment (Correct answer)
- Hearing loss only
- Visual field defect
Correct answer: Working memory impairment
Working memory is essential for holding intermediate results during sequential subtraction.
Question 6: On the MoCA, the serial 7s task contributes a maximum of how many points to the total possible score of 30?
- 5 points
- 2 points
- 3 points (Correct answer)
- 1 point
Correct answer: 3 points
The serial 7s subtraction task is worth a maximum of 3 points on the 30-point MoCA scale.
Question 7: A patient answers the serial 7s as: 93, 86, 80, 73, 66. How many subtractions were correct?
- 2 (Correct answer)
- 3
- 4
- 5
Correct answer: 2
Only 93 and 86 are correct; 80 should be 79, and subsequent answers inherit the error, so only 2 are correct.
MoCA Calculation Skills 3
The MoCA serial 7s subtraction task is primarily designed to assess which cognitive domain?