We can sum the elements of a vector using the `sum()`

function.

Similarly, `mean()`

and `prod()`

functions can be used to find the mean and product of the
terms.

## Example: Vector Elements Arithmetic

```
> sum(2,7,5)
[1] 14
> x
[1] 2 NA 3 1 4
> sum(x) # if any element is NA or NaN, result is NA or NaN
[1] NA
> sum(x, na.rm=TRUE) # this way we can ignore NA and NaN values
[1] 10
> mean(x, na.rm=TRUE)
[1] 2.5
> prod(x, na.rm=TRUE)
[1] 24
```

Whenever a vector contains `NA`

(Not Available) or `NaN`

(Not a Number), functions such as
`sum()`

, `mean()`

, `prod()`

etc. produce `NA`

or `NaN`

respectively.

In order to ignore such values, we pass in the argument `na.rm = TRUE`

.