First question is what adc1 and adc2 units are? Are they mV, V, or adc_counts? Translation would depend on that. But basically with a 0.1 ohm shunt you should see 0.1V drop for every amp of current. So if the unit of amps is volts, just multiply by 10 to get amps or multiply by 10000 to get milli-amps:

A=V/0.1= V*10 or mA=(V*1000)/(0.1)=V*10000

If the adc1 and adc2 results are in milli-amps, then divide by 100 for amps or multiply by 10 for millamps:

A=(mV/0.1)/1000=mV/100 or mA=mV/0.1=mV*10