Question: How many blocks can 999 lines divide a plane into?

My understanding is that 999 lines can theoretically intersect 999 lines to maximize the cut.

Have a zero line

One plane: 1

There are 1 line

The original plane is retained and a new plane is added, that is, 1+1

Two lines intersect

The original plane is retained, and two new planes are added, namely, 1+1+2

Three lines intersect

The original plane is retained, and three new planes are added, namely, 1+1+2+3

Four lines intersect

The original plane is retained and four new planes are added, namely, 1+1+2+3+4

There are 999 intersecting lines

That is: 1 + 1 + 2 + 3 + 4 +… +998+999 = 1+(1+999)*999/2 = 499501