Instead of saying "100 dollars," we would say "100 units."
Instead of "£100," we would say "100 units in UK currency."
For Bitcoin, instead of "0.003 BTC," we might say "100 units in Bitcoin."
Wait, what's the reason you can turn 0.00
3 BTC become 100 units? it doesn't make sense. But, if it's a typo which actually it should be 0.001 BTC, it's still make some confusion since 1 Bitcoin equal to 100 million satoshis.
It's better to treat "satoshi" is the unit in Bitcoin, so 100 units in Bitcoin should be 100 satoshis or 0.00000100 BTC.