Visualising Landau level filling and the IQHE

Today I gave a lecture on quantum magnetic oscillations (de Haas van Alphen effect) and determination of the Fermi surface. I struggled to find a simple explanation of how Landau levels lead to oscillations periodic in 1/B.
I briefly mentioned the Quantum Hall Effect. In preparing the lecture I found a nice simulation on Wikipedia which shows how as the magnetic field B increases the Landau level filling varies and this is associated with transitions between Landau level plateaus.