The proposed revision of SI units would embed Planck's constant into the definition of the kilogram, as a fixed constant of nature. Traditionally, Planck's constant is not readily interpreted as the size of something physical, and it is generally only encountered by students in the mathematics of quantum physics. Richard Feynman's path integral formulation of quantum mechanics allows a neat visualization of the constant as the circumference of a surveyor's wheel for measuring action along each path, making Planck's constant a natural yardstick, almost literally. This approach is shown to have other benefits in the presentation of other basic quantum phenomena.