In the borrow pit method for computing earthwork volume using a grid, if the corners of a cell are at elevations h1, h2, h3, h4 and the final formation level is h0, the volume per grid square of area A is:

Borrow pit grid: each grid square has 4 corners. Volume = A x [(h1+h2+h3+h4)/4 - h0], where A = area of square, h0 = final level after excavation. Corner heights contribute 1x, 2x, 3x, or 4x depending on how many squares share the corner. Total volume = grid size^2 / 4 x Sum(n_i x h_i) - N x h0 (N = total grid squares).

ScoreCardAI links this solution with subject, topic and difficulty signals so your scorecard can identify weak areas after a full mock test.