Multiplying in binary | Applying mathematical reasoning | Pre-Algebra | Khan Academy

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[minyo]

i love short videos like this that go directly to the point

[bnkm]

why did we add the zeros at the star of the second and third line ?

[thatGUYbehindthemask]

how i would pronounce binary numbers, just because he asked at the end.

101101
un-oh-biun-oh-un

100101
un-bioh-un-oh-un

111010
triun-oh-un-oh

un stands for one
o stands for zero
you can combine strings of the same oh or un by saying bi-tri-quad etc beforehand to specify the number of repeating digits.
maybe theres even room for word to specify repeating sequences along with how many times they repeat, but i havent thought it that far through yet.

[jinmyungkim]

this guy is better than my professor's 45min of lecture

[ultimategamer]

Binary!!! Computers are such awesome things...

[justvictorgd]

3:39 I have a name for this number! >:D

When translating 10, 1101 to words, I call it "Two Nib en-five"

My system for speaking binary numbers out loud actually works on quadruplets of bits, so it's pretty similar to hexadecimal.

"Nib" is equal to 1, 0000 and it functions almost exactly how thousands do in decimal. It doesn't have detail by itself, but it's used to achieve larger numbers. "Two Nib" is equal to 10 * 1, 0000, or 2 * 16.
"Two" is still equal to the quantity of 2. Quantities from "Zero" to "Seven" have the exact same names, actually!

The next number essentially use the same words, just with a small prefix.


Instead of "Eight" through "Fifteen", the names go "En-zero" through "En-seven".
The "En-" prefix stands for "enhanced", and it determines whether or not the leftmost bit inside the quadruplet is active.

0101 = "Five" (no prefix, the leftmost bit is a zero)
1101 = "En-five" (yes prefix, the leftmost bit is a one)

[gronejczyk]

this isnt my accout it was logged on the school computer so now im liking the most randomass videos to ruin this guy's algorythm

[erikpinter]

Thanks so much! I am preparing for my exam and this video helped me a lot!!!

[Astatos-Lota]

Oh my god that made more sense that the 1 hour lecture

[samtg]

Thank you for the videos they are very helpful !

[XXAylinXX]

was breaking my brain trying to figure this out from the textbook omg thank you!!

[sethbarrett]

These videos need to use tougher examples. Anyone could figure this example out on their own.

[zachaeusjohnizrijeanjacque]

Realy helpfull for me helped me in my computer exam thanks

[mathextsgd]

thank you khan academy for teaching me when my professors wouldnt

[pepper]

2:06


I've been doing multiplication since grade school, and that was just new to me xD

I usually add the product under the second to the last digit, but I never understood why.

Now I know. .-. XD

[KiKi-fyev]

The last part were u used base-2 i didn't understand from that one

[Edward-gbdx]

The author should do the cool naming exercise he mentioned - giving names to binary numbers! Maybe two legs / or something like that? :-D

[htww]

I came here thinking there would be a simpler solution, like some cheat code, because this type of multiplication is intuitive since we've been doing it from elementary onwards.

[LilRitchr]

I don’t understand why we have to do this in school rather than multiplying the decimal numbers and then just converting the result into binary?

[tymothylim]

Thank you very much for this video :) It was very helpful :)