The integer part of x is the integer n such that . (There is exactly one such integer for each real x.) It is usually denoted by [x].

For example:

[3.14]=3

[0.52]=0

[1]=1

[-1.26]=-2

So 2 and 2.5 are in relation, since [2]=2=[2.5], but 1.5 and 2.5 are not.

Hope this helps.