Well the lid of it has direction's on it. I follow them but it doesnt seem to work. This is what it say's to do...

1. Press On/Off/Tare to turn on the scale and wait until it display's 0.0
2.Press UCAL key once and the scale show's 'Cal' and the 0.0 flashing.
3. Press UCAL again and the scale show's the full capacity weight.
4.Put the standard weight on the center of the platform, then press UCAL. The scale will show PASS and full capacity weight.
5.Take weight off platform, press On/Off/Tare and hold for 3 second's to turn the scale off. Calibration is completed.

I've followed these instruction's exactly. What could I use that weigh's 100 gram's? I don't know anyone who would have a weight, nor do I have one.