Give a Fuck
From Federal Burro of Information
What's the SI unit of concern? It's the the giveafuck (GaF). Which gives us the kilogiveafuck (kGaF), the megagiveafuck (MGaF) and of course the gigagiveafuck GGaF). But it also gives us the milligiveafuck (mGaf) , the microgiveafuck (µGaF), and the nanogiveafuck (nGaf).
A single giveafuck has been defined as something you would do on a Friday morning. If you care to do it on a Friday morning, then you care 1 giveafuck. Note however that external factors affect how much something is cared for. For example on Friday afternoon, the thing that you cared about 1 giveafuck (GaF) in the morning, you now care about 1/1000 of a giveafuck, or 1 milligiveafuck (mGaF).
Science!