I often notice transactions such as:
Where funds from the address
3PU with 1.38 BTC are split to itself (1.35 BTC) and
3PUui (1.38 BTC) -> 37Ekc (0.0278 BTC) -> 3Puui (1.3519 BTC)
I am wondering why the transaction doesn't look like:
3PUui (0.0279 BTC) -> 37Ekc (0.0278 BTC)
I read from this question that an input must be completely consumed in the transaction, so if I have received 1.35 BTC during the last transaction, if I refer to it, I must consume the 1.35 BTC.
However on https://coinb.in/#newTransaction I can see the amount can be specified for each input. So why should I need to mention the input amount if it is already set by the previous transaction?