Khan Academy on a Stick
Prealgebra
No way, this isn't your run of the mill arithmetic. This is Prealgebra. You're about to play with the professionals. Think of prealgebra as a runway. You're the airplane and algebra is your sunny vacation destination. Without the runway you're not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We're about to take off!
 Negative numbers and absolute value (22 videos)

Factors and multiples
(19 videos)
Understanding and finding factors and multiples. After these videos, you'll be ready for fractions.
 Decimals (78 videos)
 Fractions (96 videos)
 Ratios, proportions, units, and rates (33 videos)

Applying mathematical reasoning
(40 videos)
You already have many tools in your mathematical toolkit. In this topic, you'll use these in settings that you're likely to encounter in the real world!

Exponents, radicals, and scientific notation
(36 videos)
Understanding and solving exponents without algebra.

Arithmetic properties
(42 videos)
This tutorial will help us make sure we can go deep on arithmetic. We'll explore various ways to represent whole numbers, place value, order of operations, rounding and various other properties of arithmetic.

Measurement
(17 videos)
From length to area to volume to time, thinking about how we measure things.