steps
1. search for module
    pip search math(module name)  (pip used for python package installer)
2. download the package
MDHARMAL-M-Q4AL:numbers root# pip download math-addition
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting math-addition
  Downloading https://files.pythonhosted.org/packages/9b/47/785f53e8cecadadc9c5630543cc1ee96332570008e2df8c069bfd7d1629b/math_addition-3.0-py2-none-any.whl
  Saved ./math_addition-3.0-py2-none-any.whl
Successfully downloaded math-addition
MDHARMAL-M-Q4AL:numbers root#

3. pip install module
MDHARMAL-M-Q4AL:numbers root# pip install math-addition
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting math-addition
  Using cached https://files.pythonhosted.org/packages/9b/47/785f53e8cecadadc9c5630543cc1ee96332570008e2df8c069bfd7d1629b/math_addition-3.0-py2-none-any.whl
Installing collected packages: math-addition
Successfully installed math-addition-3.0
MDHARMAL-M-Q4AL:numbers root#

4. import module
>>> import math
>>>
