An example of Cohen’s Number Field Drawings, Untitled, 1969, comprises a sequence of numbers spread throughout the surface. Multiple iterations of numbers three through nine appear in clusters and snake-like winding forms following a logic unknown to the viewer. Produced a year into his tenure at Stanford, the arrangement of numbers in this work was produced digitally. Using a DITRAN code, an iteration of ASA Basic FORTRAN, to generate the distribution of numbers, the output was subsequently stencilled onto the canvas surface and coloured by hand. The Number Field works are similar to the slightly earlier Contour maps; these works were also grounded in the instruction of distributing digits at random and subsequently growing additional digits around the initial ones - continuing until they reach zero or a cell already filled with a number. Although the logic follows suit between the Contour Maps and Number Fields, the two series’ are visually very different, with the numbers in the later works distributed at variable distances from each other rather than in a rigid grid.

In smaller works from the Number Field series, a CDC computer and a Calcomp plotter were used to execute the works - lending greater precision and definition to the rendering of the digits. Introduced in 1959, the Camcomp 565 drum plotter was one of the first computer graphics output devices commercially available. From the plotted outputs, Cohen would then transfer the works onto canvas by hand.