Answer:
non-examples include:
numbers with digits after their decimal points: 0.49, 1.28
irrational numbers: sqrt(2), φ
transcendental numbers: e, π
imaginary and complex numbers: i, -3i+2
for an alternative explanation, here is a number line:
all integers (natural numbers above 0, 0, and negative integers) are on this number line. they are discrete, equally spaced points on an infinite line.
as for non-examples:
rational non-integers are defined points on the number line, but are in between the discrete points that are integers
irrational and transcendental numbers are on the number line, but cannot be assigned a fixed point since they have infinite digits after the decimal point, which do not follow a recurring pattern.
complex numbers with imaginary parts cannot be represented on a 1-dimensional number line; instead, a 2-dimensional plane is used to represent the separate parts. this has two axes; 1 real axis, and 1 imaginary
