# Fast at basic math



## Phishfry (May 19, 2019)

In my trade one of the hallmarks of a good recruit is the ability to do math quick in your head.
Sometimes this becomes complex math as it may require metric to imperial conversion as well as fraction to decimal conversion.
Lots of quick geometry as well as adding big numbers. We used to do alot more but computers fixed all that...

What kind of fast mental math do you do at work? .03937 is pretty much burned in my ROM.


----------



## Phishfry (May 19, 2019)

The advent of the cellphone calculator has also changed my workflow. I used to have a separate calculator until i finally gave up.
Now its all done from my flip-phone.


----------



## Phishfry (May 19, 2019)

What is weird is why do I use the longer .03937 conversion for mm to inch.
When the shortest approach is divide by 25.4
The multiplication constant was taught to me early and burned in.
Strange thing the brain is.


----------



## mfaridi (May 19, 2019)

can use Python too.


----------



## Phishfry (May 19, 2019)

Python is OK but the PIP ecology scares me.
The repository seems wild-west and if you use PIP on FreeBSD it works but you lose security features of FreeBSD package system.
So I am on neutral with python. Probably a great scripting language.

I still have not gone much beyond G-code in regards to programming.
Basic lisp is embedded in my head too because of Acad/Autolisp.

But with Autocad/Master/SolidCAM you basically can be a CNC programmer with no trigonometry skills at all.
The old timers would be rolling in their graves.
How can you be a machinist and not know trig.


----------



## Spartrekus (May 19, 2019)

Phishfry said:


> In my trade one of the hallmarks of a good recruit is the ability to do math quick in your head.
> Sometimes this becomes complex math as it may require metric to imperial conversion as well as fraction to decimal conversion.
> Lots of quick geometry as well as adding big numbers. We used to do alot more but computers fixed all that...
> 
> What kind of fast mental math do you do at work? .03937 is pretty much burned in my ROM.



For educative, one can prepare a list of calculations, and it is possible to show/hide it and practice  them. 

that's math, without Python and any single other files.








						GitHub - spartrekus/equcalc: Advanced mathematical Equation calculator, using a twin pan file viewer.
					

Advanced mathematical Equation calculator, using a twin pan file viewer. - GitHub - spartrekus/equcalc: Advanced mathematical Equation calculator, using a twin pan file viewer.




					github.com
				




Today, maybe, I saved to you be scared of python and other java languages


----------



## Crivens (May 19, 2019)

I still need to find the time to learn the slide ruler. Still got a family heirloom from  my grand dad.


----------



## Spartrekus (May 19, 2019)

Crivens said:


> I still need to find the time to learn the slide ruler. Still got a family heirloom from  my grand dad.


wow, still existing.
Long time I haven't used one.
Can you make a picture of this slide ruler? US was manufacturing them, well, *joke* chinese market hasn't copied/cloned this today  

Furthermore, it was quite fast to get results with slide ruler.
The original Apollo 13 movie got  examples of use.
Maths saved the day.




_View: https://www.youtube.com/watch?v=HD0NfshRyh8_


----------



## Crivens (May 19, 2019)

I need to dig around for that one...

Re Apollo - you know why Buz Aldrin came along, do you? Also, there is a talk about the Apollo board computer on media.ccc.de somewhere. Absolutely amazing tech.


----------



## leebrown66 (May 19, 2019)

My Dad let me use his slide rule.  I wasn't allowed to touch the electronic desk-calculator we had.


----------



## fernandel (May 19, 2019)

All mine high school and on the university a little less I had to  use "Rechenschieber":
https://de.wikipedia.org/wiki/Rechenschieber
I have two still and both works .


----------



## Spartrekus (May 19, 2019)

that's a cool one.

de:
do you still have the books, with cos(), sin(),... ?

sounds interesting. more information would be great.
please could you eventually, if time, comment on that:
"Re Apollo - you know why Buz Aldrin came along, do you? Also, there is a talk about the Apollo board computer on media.ccc.de somewhere. Absolutely amazing tech."


----------



## Crivens (May 19, 2019)

I did not know they came in round...


----------



## aragats (May 19, 2019)

This is the last one I used:


----------



## mfaridi (May 19, 2019)

We can find many applications in  ports tree about mathematics.


----------



## Crivens (May 19, 2019)

Buz was the backup in case the electronic died on the way. He was the one who had developed the math for the brake & take off control, so he was the best bet to do the  calculations by hand in the radio shadow of the moon. 

And the talk about the hardware is here: media.ccc.de/v/34c3-9064-the_ultimate_apollo_guidance_computer_talk


----------



## Spartrekus (May 19, 2019)

mfaridi said:


> We can find many applications in  ports tree about mathematics.


running on java?


----------



## Phishfry (May 19, 2019)

You better add a TM to that mark or Lounge-suit Larry E. will get you.
Kinda fixated on J#va today?


----------



## Spartrekus (May 19, 2019)

Phishfry said:


> You better add a TM to that mark or Lounge-suit Larry E. will get you.
> Kinda fixated on J#va today?


yeah, maybe, thanks. 
It was joke about it.


----------



## SirDice (May 20, 2019)

Phishfry said:


> What kind of fast mental math do you do at work?


I can type dc(1) really fast, does that count?


----------



## bookwormep (May 20, 2019)

The co-founder and lead engineer of Apple Computer, Steve Wozniak, has been said to have
scored an 800 on math section of his SAT (college aptitude testing)..(perfect score)....
For me, my math section score was about 550-600, which I thought was okay.


----------



## badbrain (May 20, 2019)

Spartrekus said:


> running on java?


Why forgot python, gnuplot and pyqt5?


----------



## badbrain (May 20, 2019)

And there're many other solution like sage, maxima...


----------



## aragats (May 20, 2019)

SirDice said:


> I can type dc(1) really fast, does that count?


That's a good one, but I better like math/calc, it seems more useful to me: I like typing long expressions and easily modify them on the command line.


----------



## Spartrekus (May 21, 2019)

badbrain said:


> Why forgot python, gnuplot and pyqt5?


gnupot is cool  indeed.
command line is always useful indeed aragats.


----------



## badbrain (May 26, 2019)

Spartrekus said:


> gnupot is cool  indeed.
> command line is always useful indeed aragats.


And I hate CLI. I use gnuplot via WxMaxima.


----------

