
| Topic | Author |
| Introduction to Ratios (new HD version) :Questions/Thoughts? | Ashish Gupta (13) |
| Scientific Notation Examples :Questions/Thoughts? | Ashish Gupta (13) |
| Scientific Notation :Questions/Thoughts? | Ashish Gupta (13) |

This is a video lecture series by Salman Khan. In this course he explores pre-algebra in an easy-to-understand and engaging manner. Topics include operations, fractions, logarithms, and ratios. Watch the videos and use the discussion boards to ask and answer questions.
Source: Khan Academy
License: Creative Commons 3.0
Donations: Donate to the Khan Academy