'Russian' Multiplication

[TonyF273]

half of 23 is 11?? haha

[dadoctah]

I never understood how this worked until I had to write a machine-language program to multiply in binary on an old 8-bit computer. It's the same as the old "multiply one digit at a time and shift the answer over, then add down the columns", only in base two. In binary:

"Multiply by one" = "copy down the other number"

"Multiply by zero" = "skip the other number"

Last bit tells you even or odd

"Shift to the left by one place" = "double"

"Shift to the right by one place" = "halve"

[ghostbirdofprey]

@dadoctah Just as how learning a second language can help you to understand your first language, if we treat different number systems as different languages, then learning an alternate number system can help us understand decimal.

I have found, as you have, that knowledge of aspects of binary and decimal mathematics can cross pollinate, so being more adept at one can improve skill at the other.

Now I just need to learn how to work in hex natively.

[Culerda]

more easy use the calculator:))

[returnoftheramble3]

i have some demonic things like my triangle. See, a long time ago, I noticed that people would make up all sorts of theories and not be saying anything, and they were bashing me with it... so I made presents. that's right. I don't study theory. LOL

[returnoftheramble3]

doesn't really amaze me. I have all sorts of number tricks. It just pisses people off. The reason is because they know exactly what they're taught, and I have to be wrong somehow because it's too easy, and they missed it. I'm still thinking about making a little math book, but I'm afraid to.

[TTTTrangTTT]

wow , this is hard ! can't understand it 

[bbiancass]

nice trick, but it takes longer than the... normal multiplication

[Inu981]

i am multiplying 239 x 47 but either the 47 side is either all odd or all even wahhh

[cembry90]

239 x 47

119 x 94

59 x 188

29 x 376

[14 x 752]

7 x 1504

3 x 3008

1 x 6016

6016+3008+1504+376+188+94+47 = 11233

[Inu981]

Thanks!

[JugglingPol]

wow, that was amazing. definately gonna use that whenever i can

[Quine0Quine]

Wow! - I so want to know how that works!