Friday, October 25, 2019

Surds

Surds - what a fabulous topic to teach! I dear the abundance of resources available as well as I’ve listed but about of my favourites below.

Two things I e'er produce when didactics surds:
  • Pupils listing the source twelve foursquare numbers inwards their books for reference throughout the lesson. They demand to readily recognise foursquare numbers inwards social club to simplify surds as well as hence the to a greater extent than they exercise listing them, the better.
  • When manipulating expressions containing surds (eg expanding brackets) I brand comparisons to what they already know virtually algebra. For event √2 as well as √3 tin hold upwards sentiment of inwards the same means as x as well as y (ie non ‘like terms’) whereas 2√3 as well as 5√3 tin hold upwards sentiment of inwards the same means as 2x as well as 5x (ie nosotros tin add together them to learn 7√3).

The NCETM suggests a yoke of prissy ‘hooks’ for getting started didactics surds:
  • Ask pupils to uncovering a means of drawing a occupation alongside a length of just √5 units (the hypotenuse of a correct angled triangle alongside sides 2cm as well as 1cm) 
  • Ask pupils to separate the length of an A4 slice of newspaper yesteryear its width. Repeat for A3 as well as A5. What produce they notice? (The answer is e'er √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 but about groovy didactics resources (there's hundreds to a greater extent than online). Most of these travel as good at GCSE as well as Influenza A virus subtype H5N1 level:

For a lovely laid of surds problems, come across 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 option method for simplifying surds: