To learn about this topic, let’s start with a problem.

Snippet of code below is to be implemented:

a=13 |

As much as I have learnt about arithmetic operations, there are 4 kinds of feasible solutions for BASH.

`$(( expression ))`

gives the result of the calculation- Also you can do calculation using
``expr expression``

- To do calculation and assign the result directly, you can try this:
`((result = $a + $b))`

as well as`((result = a + b))`

, where result,`a`

and`b`

are all shell variables. - Using bc calculator with pipe.

For that problem, and with the help of the hints, we can provide 4 structurally different solutions respectively.

# Sol.1 |

If you try them all out, you will find that only the last solution gives float number as result. So one thing you should bear in mind is that built-in calculation of bash only does integers. To do float points, you must get the assistanse of external tools, in which `bc`

is the one mostly referred to.

Built-in arithmetic operation in bash only does integers.

With this basic experience with arthmetic operation of bash and help of GOOGLE SEARCH, you can now solve more problems.