I need to do a bunch of simple math on a collection of number variables. Things like:

```
x,a,b,c :: MaybeNumber
x = a * (b + c)`
```

where all of the variable are Maybe Number. I do want to keep the values wrapped in Maybe, even something like

`(+) <$> b <*> c`

or

```
do
b' <- b
c' <- c
pure $ b' + c'
```

is pretty ugly and really hides the formulas, especially when there are multiple terms.

Am I missing something?