# Using an arithmetic expansion

We can use two different ways for evaluating arithmetic expressions:

```    \$(( expression ))
\$[ expression ]
```

Learn arithmetic operations using the preceding mentioned arithmetic expansion:

```    \$ a=10
\$ b=20
\$ c=\$((a + b))
\$ echo \$c  ```

During arithmetic operations, we may need to find the square or cube of any given number. These operations are called exponent operations. We can perform exponent operations as follows:

```    \$ a=5
\$ b=3
\$ expo=\$[ \$a ** \$b ]    # This is equivalent to ab
\$ echo \$expo
125  ```

This is the result of the 53 operations:

Another way to do arithmetic expansions is as follows:

```    \$ B=10
\$ A=\$[B + 10]
\$ echo \$A
20
\$ echo \$[ 3 + 4 - 5 ]
2

\$ echo \$[ 3 + 4 * 5]
23  ```

Arithmetic multiplication has precedence over addition. ...

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