I’ve seen the cognition test trump is so proud of taking that towards the end of the test it asks the person to count backwards by 7. I could not do this to save my life. Am I demented? The rest of the test I’ve seen seems fairly easy for a normally functioning person, but that task is well beyond me.
It is probably the most difficult part of the test, and it’s surely more difficult for some than for others, even dementia-free. I’m not great at doing math in my head, but I can do this without too much hesitation. My strategy is, I split the difference of the ‘7’ around each number ending in ‘0’:
- 100
- 93 (so far, easy peasy)
- 86 (at this point I mentally subtract the 3 from 93 to get an even 90, then I subtract the remaining 4 to get 86).
- 79 (then I just continue with that strategy-- mentally subtracting 6 to get an even 80, then 1 to get 79 is pretty easy).
…and so on. That method might seem clunky, and others may just be able to do the count back automatically, but this method works for me. Try it.
I think the important thing is that this is not the only part of the test your cognitive ability is graded on. Also, I’m sure many people stumble on it, but those with cognitive issues will do really badly. In other words, you’re probably not expected to be 100% perfect on the count to be cleared of cognitive issues.
Disclaimer: I’ve only taken the test from an online copy out of curiosity, not in an ‘official’ setting.
Most people will probably just go “99 98 97 96 95 94 93” in their head, and so on for each successive number. It’s a bit brute-force, but it works. Someone with dementia will probably lose track of where they are and get the counts all screwed up.
If I were going to break it down, I would subtract 10 and then add 3 at each step. Mentally it’s just as fast, you’re doing the same thing at each step so you don’t have to figure out what the remainder is, and subtracting 10 is easier.
I do the same sort of mental math if I want to figure out what something like 9x47 is. 9x47 = (10x47)-(1x47), or 470-47, or 470-50+3=423. Easy peasy.
Most people don’t do that type of mental math in their head though.
Yeah, that’s good. Better than my strategy.
Not even ‘and so on’. From what I’m reading, what you posted would be enough.
Serial 7s: Administration: The examiner gives the following instruction: “Now, I will ask you to
count by subtracting seven from 100, and then, keep subtracting seven from your answer until I
tell you to stop.” Give this instruction twice if necessary.
Scoring: This item is scored out of 3 points. Give no (0) points for no correct subtractions, 1
point for one correction subtraction, 2 points for two-to-three correct subtractions, and 3 points
if the participant successfully makes four or five correct subtractions. Count each correct
subtraction of 7 beginning at 100. Each subtraction is evaluated independently; that is, if the
participant responds with an incorrect number but continues to correctly subtract 7 from it, give
a point for each correct subtraction. For example, a participant may respond “92 – 85 – 78 – 71
– 64” where the “92” is incorrect, but all subsequent numbers are subtracted correctly. This is
one error and the item would be given a score of 3.
I’ve done this by mentally picturing my fingers.
knowing my luck, if I learn to use this strategy, then they’ll change
the test to subtracting 6s.
You only have 7 fingers?
This I could do.
On one hand, sure 
I bet it is to grade, (if you can somehow do it, even if it takes an extra minute per)!the way you can mentally stay on the task. Not whether you do it so quickly or correctly.
I’m guessing.
I figure percentages at the store: as in 30 percent off. Price 25 dollars: 10 percent 25 = 2.50 + 2.50 + 2.50 = 7.50, so 7.50 off. 17.50. I like the scenic route.
Backwards from what number? I shouldn’t have any problem regardless. If the last digit is 7 or greater, very easy. If it isn’t, borrow 1 in my head.
It’s one question. If you don’t get it but you get more than the cut-off number, you’re “grossly cognitively intact,” as we say in the language of my people. Also, it’s a screening instrument. Getting a lower score than the criterion means you should be further assessed. It doesn’t generate a diagnosis.