What menial mental task do you struggle with?

[FallenApple]

Reciting the alphabet backwards.

Oh and mental arithmetic.

 

[tony873004]

Linear algebra transformations by hand.
A lot of them are just a whole bunch of 4th grade multiplication problems done in the right order. I have no trouble with the order. But somewhere along the line, 5*4 is going to equal 9 and ruin the whole thing.

 

[sanman]

Row-reduction in Matrices (linear algebra)

When I have multiple equations to solve for, then I like to write them all down and solve them the old fashioned way. I hate putting them into a Matrix and trying to use Row-reduction to solve them. It feels too abstracted from the original context.

 

[Alan McIntire]

"Lefty loosy, tighty righty" makes no logical sense. I use the alliteration, "clockwise to close."

 

[Alan McIntire]

"Lefty loosy, tighty righty" makes no logical sense. I use the alliteration, "clockwise to close."

 

[eigen]

Whenever I need to know something like 'how many numbers are divisible by 5 in the range 0-100?'

Is it 20? 21? Variants of this (edge cases in counting) confuse me every time and I always need to double-check.

 

[julian]

I used to go "never eat shredded wheat" to work out NORTH, EAST, SOUTH, WEST until somebody chuckled abou it, now I seem able to bypass the Mnemonic device.

 

[muscaria]

Natural units for systems: making quantities dimensionless and expressing everything in terms of these units. Although it is just basic algebra, sometimes it doesn't feel all that natural (pun intended) for my brain.. Maybe the fact that I find it to be painstakingly meticulous and boring plays a part in that :p

 

[dkotschessaa]

I used to go "never eat shredded wheat" to work out NORTH, EAST, SOUTH, WEST until somebody chuckled abou it, now I seem able to bypass the Mnemonic device.

North south I'm pretty good with. West-East I always have to picture "WE" to get right.

 

[jackwhirl]

...abou it...

I make mistakes like this a lot when writing by hand.

 

[Faiq]

Identities surrounding sin x and cos x

 

[sa1988]

Here's a weird one. When I notice I've missed a word in some sort of online text input (such as this), I'll go back to where the missing word is and write that word. After submitting it I notice I wrote the word in the wrong place, usually a notch too far to the left or write.

e.g. "Here's example sentence which I'll probably get wrong"

Oh bummer, I got it wrong.

After edit: "Here's example an sentence which I'll probably get wrong."

 

[late347]

Putting the usb cable into the laptop correctly...

For some reason it always takes 3-4 tries even though you're supposed to do it in 1-2 tries( if you are very good)...

Sometimes I mix up the months of april and may in my brain. Which is the 4th which is the 5th. Best to always count forward from January...

For English language spelling rules for individual letters of the alphabet. I always have to sing the English alphabet song inside my brain, so I can choose the correct i and e.

Because my native language Finnish alphabet song has a totally different tune and pace to it.

Strangely enough I was able to memorize the German language alphabet spelling without the alphabet song being replayed in my brain.

Now that I think about it I am not sure if we ever learned any German alphabet song in early school grades. German was my first foreign language at school and the second foreign language was English. Third being Swedish.

 

[OCR]

Oh bummer, I got it wrong.

Yes, it seems you might have...

...usually a notch too far to the left or write.. ←...

Just funning you... I do that same thing, alot a lot ....

 

[sa1988]

Yes, it seems you might have...

...usually a notch too far to the left or write.. ←

Just funning you... I do that same thing, alot a lot ....

Hahaha that's absolutely amazing! A text based Freudian slip?

Anyway here's another one, more on topic I think:

When dealing with matrices in notation such as $A_{mn}$ I always have to think really hard about which index is rows and which is columns, pretty much saying to myself, "Ok, it's m times n, rows times columns, so m is the rows, which are the horizontal ones!"

 

[EnumaElish]

Putting the usb cable into the laptop

https://www.physicsforums.com/attachments/112167

 

[dkotschessaa]

When dealing with matrices in notation such as $A_{mn}$ I always have to think really hard about which index is rows and which is columns, pretty much saying to myself, "Ok, it's m times n, rows times columns, so m is the rows, which are the horizontal ones!"

Gahhh! Yes! I still can't keep this straight.

 

[PeroK]

"Thirty days hath September..."

I always used the number of days in each month to remember the rhyme! Is that a reverse mnemonic? The numeric pattern seemed more logical to me. Anyway, it was only a few years ago that I realized that it's supposed to be the other way round!

 

[houlahound]

I can not do counting problems involving combinations & permutations etc without writing a lot down. I kid in my high school class failed at pretty much everything but when we did probability he would just yell out the correct answer as soon as the teacher finished saying it. the higher achieving students were frustrated because 10 minutes later after a lot of working out we would verify this kid was correct.

don't know what it was but he just had an instant mental picture of counting re probability.

still now 30 years later I have to write every probability problem out explicitly and do every step. I actually still don't get it even when I get the right answers.

there are a lot of hard topics I know that are actually tough, probability is supposed to be a general topic every high school student can do without much drama, it is not even considered an advanced topic - it is beyond my comprehension - Bayes theorem, the null hypothesis, the old problem where the probability changes as the contestants see what is behind the door...all voodoo magic to me.

 

[XZ923]

For me this is an easy one: names and faces. I frequently find myself in situations where I'm talking to someone and thinking "this person knows my name, we're supposed to be at least friendly, I should know their name!" I'm sometimes asked by people who are aware of my secret shame "how can you memorize strings of 40 or 50 numbers (which I do for all my important passwords) without a problem but you can't remember a name?"

 

[dkotschessaa]

I can not do counting problems involving combinations & permutations etc without writing a lot down. I kid in my high school class failed at pretty much everything but when we did probability he would just yell out the correct answer as soon as the teacher finished saying it. the higher achieving students were frustrated because 10 minutes later after a lot of working out we would verify this kid was correct.

don't know what it was but he just had an instant mental picture of counting re probability.

still now 30 years later I have to write every probability problem out explicitly and do every step. I actually still don't get it even when I get the right answers.

there are a lot of hard topics I know that are actually tough, probability is supposed to be a general topic every high school student can do without much drama, it is not even considered an advanced topic - it is beyond my comprehension - Bayes theorem, the null hypothesis, the old problem where the probability changes as the contestants see what is behind the door...all voodoo magic to me.

Don't worry.. For some reason I do better with graduate level combinatorics than the undergraduate/high school/basic counting stuff. There are so many beautiful theorems and proofs in combinatorics - for me it's easier to deal with. But don't ask me how many ways I can pull something out of a deck of cards!

-Dave K

 

[houlahound]

I might start a thread on probability so I do not derail this one and see if anyone here can help me get Bayes theorem, the null hypothesis and how the probability changes in that common school math comp question where the information behind the door changes in a fake game show.

I am not interested in calculating any right answer, I just want to be less dumb about chance math.

 

[Clairevonne]

Taking two different music classes, on both wind and string instruments I easily get the line notes mixed up- e,g,b,d, f- when I play. I can see just fine and I know how to read music, but when I sightread or even play a familiar piece I mix up those notes quite easily.

In math, it's positive vs negative signs, all the time. (and the simple 7+5= 12 vs 8+5=13)