/sci/ - Science & Math

It's easy with 4 and 8 as well. Primes are a bit harder and number theory explains properly why that is to. Learn 2 school

tip: it would be easier if you had the same amount of fingers as the man in the pic you posted

because base 10

although it 4x8 actually takes you significantly longer than 5x10 you are probably functionally retarded

>>4086720
>Never learned multiplication tables due to shit elementary school, never needed it afterwards

>takes 6+ seconds to figure out 4x8 (I had to work it out as 16+16)

>takes ~1 second to think of 5x10

>4.0 GPA, last semester under-grad, had a 103 (3 point curves are fun) in my last mathematics class

>I'm retarded

No.

>>4086730
not understanding what <span class="math">\mathbb{"significantly longer"}[/spoiler]

Yeah, you're retarded.

>>4086738
>6 times longer
>not significantly longer

Yeah, no.

With something as low as that why cant you just go 8 16 24 32?

>>4086713

Notice the "Trailer" (Rightmost) numerals when you do Multiplication with 5 or 10.

5*1=5
5*2=10
5*3=15
5*4=20

10*1=10
10*2=20
10*3=30
...

How many diverse numerals can you notice?

Now do that with 4 and 8.

And that the explanation for your inquiry.

>>4086742
For me? ( >>4086730 )
No idea, I just instinctively did 16+16.

>>4086742
the point is it doesn't come as easy as 5 10 15 20

when you learn the multiplication tables for the first time 0 is easy, 1 is easy, 2 is easy, 3 is harder, 4 is harder, 5 is easy, 6 is harder, 7 is harder, 8 is harder, 9 is harder, 10 is easy. etc

4 is easy in binary
100*1=100
100*10=1000
100*11=1100

Hey I'm fairly decent with calculus/algebra and shit (2nd year math major) but I can't mental math for shit. It's embarrassing.

I keep getting As/Bs in math classes but I feel like I actually suck at math somehow.

Can anyone relate?

>>4086760
>That's what butthurt haters actually believe
Cry more.

Because the one's place has few options (5/0, or just 0) in those cases. Everything else is more complicated there.

The problem is the Multiplication table.
That's why it's so hard to do it, because you were never taught HOW to multiply, you were simply forced to learn a nifty trick without any understanding of HOW to do it, until so much later in life you couldn't overwrite it's function in your brain and do it RIGHT.

>>4086779
>algebra
>2nd year math major

I sure hope you mean abstract and linear algebra

because you are in base 2*5

>>4086780
100*100=10000
100*101=10100
100*110=11000
100*111=11100