Two Powerpoints for introducing and practicing standard deviation.

Standard Deviation 鈥榃hat it Means鈥� introduces the idea of spread with some examples then gives the full standard deviation for pupils to practice.

Standard Deviation 鈥楶ractice Questions鈥� gives some examples for pupils to practice and full solutions.

I鈥檝e also included short versions of each Powerpoint as a PDF if you prefer to use these as handouts.

Edit: added a page explaining about the standard deviation formulas