A fraction.
2.45 is a fraction and there is no way to represent it as a whole number. The whole part of it is 2.
A simple fraction represents a part of the whole.
5.28 is a mixed number and there is no way to represent it as a whole number. The whole part of it is 5.
7.052 is a mixed number and there is no way to represent it as a whole number. The whole part of it is 7.
6.148 is a mixed number and there is no way to represent it as a whole number. The whole part of it is 6.