Computed the work done in moving a particle once around an ellipse, anti-clockwise, in a force field defined by a differential 1-form on 3-dimensional space. In the computation we used: (i) the definition of an integral of a 1-form to simplify the problem to one involving a 1-form in just two variables; (ii) a substitution to reduce the two variables to a first year integral involving just one variable t. Then went on to define the partial derivatives and the total derivative of a 0-form in several variables. So we now understand both sides of Stokes' formula for a 0-form w in several variables. Next lecture we'll give a proof of the formula in this case.