The same source value is divided by radius-square in three visible stages. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Radius 1 creates denominator 1
The source parameter stays 16. Radius 1 is squared first, making denominator 1. The field is then 16.
r2=1,g=116=16
Radius 2 creates denominator 4
The source parameter stays 16. Radius 2 is squared first, making denominator 4. The field is then 4.
r2=4,g=416=4
Radius 4 creates denominator 16
The source parameter stays 16. Radius 4 is squared first, making denominator 16. The field is then 1.
r2=16,g=1616=1
The radius-square denominator carries the inverse-square pattern
The diagram fixes the source and moves the body outward. The table separates the three scan stages: radius, radius-square, then field.