At the moment, if you want to check whether a number is within a range of numbers (e.g. whether 3 is between 2 and 4) you have to combine two > and < checks. This isn't especially taxing but it's a bit clunky and it would be more optimal to have a command for it.
Similarly, if you want to check whether a number is within a certain deviation of another number (e.g. whether 15 is +/- 5 from 10) you have to do some careful comparison structuring. Again, possible but a little awkward and could be made easier.
_number range [_max, _min] - returns true if _number is between _max and _min, else false.
_number deviation [_target, _dev] - returns true if _number is between (_target + _dev) and (_target - _dev), else false.