split plane into set of squares

If I have set of (X,Y) points in a plane, how can I divide this plane into set of squares (with side lenght K), for example 10x10 squares to cover all the plane? the square #1 should start from (Xmin,Ymin)

X 1.33 1.89 9.27 9.46 9.2 7.43 6.08 5.57 6.7

Y 8.89 0.77 1.49 9.36 8.69 1.61 1.34 4.6 2.77

Then how can I know how many point in each square? such that

Square #1 have two points

.

Square #50 have zero point

.

Square #100 have one point