TeachEngineering
Teach Engineering: How Do You Make Loops and Switches?
Students learn how to program using loops and switches. Using the LEGO MINDSTORMS NXT robots, sensors and software, student pairs perform three mini programming activities using loops and switches individually, and then combined.
Code.org
Code.org: For Loop Fun
We know that loops allow us to do things over and over again, but now we're going to learn how to use loops with extra structure built right in.