"10-bit DAC" means that your DAC can produce binary values from 0000000000 to 1111111111;
ie 0x000 to 0x3ff, or 0-1023 decimal.

It's entirely up to your design how these values are scaled to represent actual weights; eg, if you choose to have 0x000 represent 0oz and 0x3ff represent 1Lb, you will have no trouble representing 0.1oz.

In general, the DAC resolution is 1/1023 of the full-scale value.
In practice, this may well exceed the resolution of the actual weighing mechanism and/or sensors...