The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Math Topics » geometry.pre-college

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Marvelous Old Way of Multiplying
Replies: 3   Last Post: May 9, 2001 11:14 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
John Sullivan

Posts: 14
Registered: 12/6/04
Re: Marvelous old way of multiplying!
Posted: Jul 8, 1994 8:50 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Now, wait. If you're actually going to count out 9*14 physical
pebbles, is it really any easier to do this than to just count
out 9 groups of 14, and then count them all?

This technique is of course the usual way used to raise a number
to a large power. If you want to find k^n, where n is several thousand
(and k is maybe 2 or 3), you simply square k repeatedly, and then
multiply together the k^2^j's which correspond to the 1s in the
binary expansion of n.

-John Sullivan

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.