Definition of mathematics :

The branch of science that deals with the numbers, quantities and shapes and the relationship between them is known as mathematics.
Definition of chemistry :
The branch of science that deals with the structure, composition and properties of substances and the changes they undergo during reaction is known as chemistry.
Definition of physics :
The branch of science that deals with the nature and properties of matter and energy and their interactions in the field of mechanics, acoustics, optics, heat,electricity,magnetism,radiation, atomic structure and nuclear phenomena is known as physics.
Definition of biology :
The study of life and living things such as plants and animals including their origin,growth, structure, function, evolution and interrelationships is known as biology.