Surds

Surds - what a fabulous theme to teach! I honey the abundance of resources available in addition to I’ve listed roughly of my favourites below.

Two things I ever create when didactics surds:
  • Pupils listing the starting fourth dimension twelve foursquare numbers inward their books for reference throughout the lesson. They demand to readily recognise foursquare numbers inward guild to simplify surds in addition to then the to a greater extent than they practice listing them, the better.
  • When manipulating expressions containing surds (eg expanding brackets) I brand comparisons to what they already know close algebra. For representative √2 in addition to √3 tin hold upwards regard of inward the same means as x in addition to y (ie non ‘like terms’) whereas 2√3 in addition to 5√3 tin hold upwards regard of inward the same means as 2x in addition to 5x (ie nosotros tin add together them to larn 7√3).

The NCETM suggests a distich of prissy ‘hooks’ for getting started didactics surds:
  • Ask pupils to notice a means of drawing a occupation alongside a length of precisely √5 units (the hypotenuse of a correct angled triangle alongside sides 2cm in addition to 1cm) 
  • Ask pupils to split the length of an A4 slice of newspaper past times its width. Repeat for A3 in addition to A5. What create they notice? (The response is ever √2)
This blog post has some to a greater extent than ideas for introducing the concept of surds. And I similar this on the history of surds.

Resources
Here’s roughly bully didactics resources (there's hundreds to a greater extent than online). Most of these travel as good at GCSE in addition to Influenza A virus subtype H5N1 level:

For a lovely laid of surds problems, run into my Problem Sets page.

Finally, if you're looking for something actually creative, cheque out this Wheel of Theodorus Art Project.



Edit 29/12/14: Thanks to @runningtstitch for suggesting an choice method for simplifying surds: