Which test is used to assess attention through mental calculation by subtracting from 100?

• A. Serial sevens
• B. Spelling backwards
• C. Digit span
• D. Remote memory

Answer: (A)

Mental attention and concentration are assessed by having someone perform a mental calculation in a running sequence. Subtracting serially from 100 requires the person to hold 100 in working memory, continuously perform arithmetic, and monitor accuracy as the sequence progresses. This combination makes it a classic way to gauge sustained attention and calculation ability during a mental status exam. Other tasks tap related skills—spelling backwards uses language and working memory for sequences, digit span focuses on immediate memory and attention, and remote memory assesses long-term recall. But when the goal is attention through mental calculation by starting at 100 and subtracting, the task is serial sevens.