This is the same for me, but I did 7+7+1, basically

So, for me it is 10-8=2. Then 7-2=5. And then 10+5=15.

Its like when you do the whole logic and calculations part and then forget to square root the number at the end.

Must have been doing a lot of base-12 math?

interesting how mathes works differently for many people. because I do 8+2 to get 10. then 7-2=5, so 10+5 = 15.

Quick mafs

I understand not everyone spends that much time with numbers when they are a kid, but having liked maths (I know, I know...), I had to add up numbers enough times to recognise the pattern. So whenever I saw ghefruifghergu8+vzeru4vgbedrzvrehb7, I knew that it will end with 5, and the preceding digit will increase by one (unless it ended with 95, but enough repetitions...).

It doesn't even take intelligence, just enough repetitions ro recognise patterns - like almost everything. The same goes for the multiplying table. 8x7 isn't 56 because of the above (rather smart!) investigation anymore, but simply because 8x7 is 56, because it was also 56 for the previous 573482967589345 times. Powers of 2, up until 20? For the first few hundred times I had to start from scratch, but after ~100 repetitions, I ended up remembering them until 64. 2^7 was easy to calculate then, it's just 64x2=128. And then it grew.

Yeah, I thought there was something more to it and am disappointed.

In my case, the mental math trick suggestion (make it 10 + 5) was intended as a way to build a skill using the provided, easy example. That type of mental math can be applied to much larger numbers, particularly when combined with other mental math tricks.

For us older folk, and unfortunately, also for some younger folk that grew up in more "conservative" small towns, borrowing and fancy math trickery was the work of the devil.
We were required to memorize the addition tables as well as the multiplication tables. And even then, addition could be done on your fingers and toes so as long as you could add the big numbers like 8 & 7 together faster than the really slow kid could take off his shoes and work it the hard way, you were considered proficient at addition.
So ya, there's a wide swath of America that just sucks at basic math.

Easy, just convert to hex, 0x0F

Take 2 from the 7

Hold on, I just need to check something. Looks around nervously

Yes, that seems easier to me as well! I was not allowed to do this according to the teacher when I was a child. They wanted me to do it in some weird counterintuitive way. But I was very stubborn and I am still doing calculations in this way. She is not the boss of the way I think!

Wait, it gets things wrong on low battery?

Same. In contexts where there are a lot of already taxing elements, there is just no mental bandwidth for switching gears and doing the calculations. So calculator it is. I do find it important to hone my skills from time to time, just not to lose them.

I'm alright when it comes to mathematics, but my memory is a swiss cheese. I'll do a calculation, context switch and 3 seconds later it's either gone or I remember incorrectly. Having things written down, on paper or in a calculator, gives peace of mind.

Totally this. Find an online calc that accepts fractions and just get it done right in a few seconds vs trying to convert to 16ths or some crap. Which is why I use all metric unless I’m forced into imperial units.

My thought exactly. I resonate with this meme but I also try to challenge myself to do math longhand on paper

No, it’s Carry On My Wayward Son.

I actually never learned this (terrible math skills from never learning basics)

Is that just adding 7+7 and then 1?