Misconceptions spread by K-6 Grade School Textbooks

CORRECTED: For every action, there is not an equal and opposite reaction.

Newton originally published his laws of motion in Latin, and in the English translation, the word "action" was used in a different way than it's usually used today. It was not used to suggest motion. Instead it was used to mean "an acting upon." It was used in much the same way that the word "force" is used today. What Newton's third law of motion means is this:

For every "acting upon", there must be an equal "acting upon" in the opposite direction.

Or in modern terms...

For every FORCE applied, there must be an equal FORCE in the opposite direction.

So while it's true that a skateboard does fly backwards when the rider steps off it, these motions of "action" and "reaction" are not what Newton was investigating. Newton was actually referring to the fact that when you push on something, it pushes back upon you equally, even if it does not move. When a bowling ball pushes down on the Earth, the Earth pushes up on the bowling ball by the same amount. That is a good illustration of Newton's third Law. Newton's Third Law can be rewritten to say:

For every force there is an equal and opposite force.

Or "you cannot touch without being touched."

Or even simpler: Forces always exist in pairs.

http://www.amasci.com/miscon/miscon4.html#newt