Here's where I'm at...
I have an old chromebook that I put Ubuntu (and Xfce) on via crouton. After installing the chromium browser, I installed nodejs via apt-get. I found that when trying to install yeoman, my node version was too old (v0.6).
So, I removed nodejs and npm:
sudo apt-get remove npm sudo apt-get remove nodejs sudo apt-get autoremove
Then followed the instructions here: https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager#debian-and-ubuntu-based-linux-distributions:
curl -sL https://deb.nodesource.com/setup | sudo bash - sudo apt-get install -y nodejs
After installing nodejs, I can run
nodejs --version to see the node version is v0.10.36.
Then, when I run
npm --version, I get no output at all.