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Topic: How teaching factors rather than multiplicand & multiplier
confuses kids!

Replies: 32   Last Post: Nov 17, 2012 11:13 AM

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Joe Niederberger

Posts: 3,298
Registered: 10/12/08
Re: How teaching factors rather than multiplicand & multiplier
confuses kids!

Posted: Nov 13, 2012 1:34 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Gary Tupper writes:
>Consider the function:
F: y= x^2 if x is rational; -x^2 if x is irrational
Appears to be continuous at a single point (0,0) only. Can be drawn
without lifting the pencil - as long as the pencil stays still.

Joe N said:
>Nice trick though.

Sorry - I should've also noted that according to the mathematicians, you would need to lift your pencil uncountably many times along the top two quadrants to skip over all the "gaps" left by the irrationals...

Better start with the bottom two quadrants> Oops! Similar problem, but infinitely more manageable ;-)

Joe N


Date Subject Author
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/12/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/13/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/14/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/14/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
kirby urner
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
kirby urner
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/15/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/17/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/17/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen
11/16/12
Read Re: How teaching factors rather than multiplicand & multiplier
confuses kids!
Joe Niederberger
11/17/12
Read Re: How teaching factors rather than multiplicand & multiplier confuses kids!
Robert Hansen

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