I am going to be going into quantum mechanics next week but first I want the students to have some understanding of waves and light. The lecture portion covers using algebra to solve for a variable, how to plug numbers into an equation, how to get the units to cancel properly by going to MKS. Some basics for solving simple physics problems, introduce some numerical and physical constants such as the speed of light, pi, Planck's constant. I calculate speed in miles per hour, Joule as a unit of energy, E=mc^2, (calculate E for 1 gram of mass).
For waves I cover period, frequency, units of frequency, wavelength, speed of propagation, wave amplitude, phase, constructive and destructive interference, sine function and other trig functions, I have them calculate the frequency of a photon given the wavelength (655 nm laser pointer).
Next week I will be showing the first part of a video called "The Power of The Sun" with John Cleese. This has an excellent description of photons in the first 1/3.