This session uses an exercise to combine making a shape out of cardstock combined with electronics to teach how to build reliably for use with the Arduino.
The idea is to put a potentiometer and an LED in a cardstock shape (not necessarily a cube), and also solder reliable connections between the components and the Arduino. This is all based on the Arduino tutorial analog input which uses readings from the potentiometer to change the frequency of the blinking LED.
By soldering cables to components and headers, and then cover those solder joints with hot glue we are protecting the connections from short circuiting and also making them sturdy for any push and pull that might be necessary with use. This is also to promote the important step away from working with breadboards. Breadboards are fine while you figure out how things should work, but if you want to build something for presentation and possibly need to move it, breadboards are unreliable.
Finally you make holes in the cardstock and poke the LED and the potentiometer out. The plugs go into the Arduino and should be much more realiable than any flimsy cables stuck into a breadboard.