[1 2 3] | sum
The above does not return the sum (1 + 2 + 3 = 6). Why? Because `sum` is a *nix utility for returning the checksum. The way to do it in Nushell is: [1 2 3] | math sum
More info at [1]. Technically, this isn't Nushell's fault; it is just delegating to an external command.* Still, I found it confusing at first.* Maybe it is time to rename `sum` to `checksum`!