Khan/khan-exercises — pull request #6178 by musicalglass (2011-11-12 21:22:38+00:00)
Title: Plugging_in_values: created next page in series

For Trello card: "Add some number variety to he plugging in exercise"
Made a new page called plugging_in_values_2 based on original page
Included negative numbers and widened the var intervals a tad