Squares Near 1000

996 sits 4 below 1000, so $996^2$996² is ${\left(1000-4\right)}^2$(1000 − 4)².

The distance comes off twice: 1000 − 2 × 4 is 992, or just 996 − 4.

Then attach $4^2$4², padded to three digits because the anchor has three zeros.