 54
 96
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peasant multiplication
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Always post answers in a "Hidecode" tag, so that others have a chance to answer the question too.
Always post answers in a "Hidecode" tag, so that others have a chance to answer the question too.
5 posts • Page 1 of 1
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peasant multiplication
so i'd thought i'd add this as a point of interest.
there is an alternate way of multiplying 2 numbers, called peasant multiplication. i'll give an example.
96 * 54 = ?
so write 54 on a column, and 96 on the column below, on the left side.
divide 54 by 2, and record the remainder.
multiply 96 by 2. divide 27 by 2 and record the remainder.
keep multiplying and dividing untill you get 0 for the division.
then, for every row on the left that has a 1 on the right for remainder, add.
this method works for any base, not just 2. here would be the same numbers, in balanced ternary.
there is an alternate way of multiplying 2 numbers, called peasant multiplication. i'll give an example.
96 * 54 = ?
so write 54 on a column, and 96 on the column below, on the left side.
divide 54 by 2, and record the remainder.
 54
 96 27 r 0
multiply 96 by 2. divide 27 by 2 and record the remainder.
 54
 96 27 r 0
 192 13 r 1
keep multiplying and dividing untill you get 0 for the division.
 54
 96 27 r 0
 192 13 r 1
 384 6 r 1
 768 3 r 0
 1536 1 r 1
 3072 0 r 1
then, for every row on the left that has a 1 on the right for remainder, add.
 192
 384
 1536
 +3072
 
 5184
this method works for any base, not just 2. here would be the same numbers, in balanced ternary.
 54
 96 18 r 0
 288 6 r 0
 864 2 r 0
 2592 0 r 2 
 7776 +
 2592
 +7776
 
 5184

phillip1882  Apprentice
 Posts: 19
 Joined: Mon Mar 14, 2011 11:05 pm
 Location: florida
Re: peasant multiplication
so... are you wanting code implementations of this?
Ask three DBAs a question, and you’ll get four different answers.
Brent Ozar

Thirster42  Guru

 Posts: 4646
 Joined: Tue Nov 11, 2008 5:49 pm
 Location: Jefferson City, Mo
Re: peasant multiplication
Thirster42 wrote:so... are you wanting code implementations of this?
Why not write one anyway?
a smile is worth a thousand kind words, so smile, it's easy!
CODE: $5
WORKING CODE: $500
PROPERLY DESIGNED & WORKING CODE: Priceless
CODE: $5
WORKING CODE: $500
PROPERLY DESIGNED & WORKING CODE: Priceless

damber  LTD Admin

 Posts: 3138
 Joined: Tue Oct 09, 2007 1:48 pm
 Location: North Wales, UK
Re: peasant multiplication
damber wrote:Thirster42 wrote:so... are you wanting code implementations of this?
Why not write one anyway?
well fine then!
Code is hidden, SHOW
Ask three DBAs a question, and you’ll get four different answers.
Brent Ozar

Thirster42  Guru

 Posts: 4646
 Joined: Tue Nov 11, 2008 5:49 pm
 Location: Jefferson City, Mo
Re: peasant multiplication
pink fuzzy slippers

chrissie1  Senior Guru

 Posts: 9475
 Joined: Wed Oct 10, 2007 7:18 pm
 Location: Belgium
5 posts • Page 1 of 1
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