Why lamportsPerSignature * 100 ?

[docongminh]

i found in this line to calculate the cost of transaction. I don't understand why we need multiple 100 for fee.

[Ashatanchik]

I also can't figure out why such a constant is chosen
did you manage to understand @docongminh ?

[cvhainb]

This fee in this case is used to check the payer's balance.

[itayLev1]

Lamports are a sub unit of solana,
Its 1SOL / 100 = lamports (think of them as satoshis in Bitcoin)
the solana network works with lamports, but users are used to see the SOL amount.
this is why you converte from lamports to SOL ( lamportsPerSignature * 100 ) when displaying to user or calculating in sol.
In this case its used to calculate the fees.
notice that the first fees implementation (calculate cost to fund) are in lamports and then the next one converts them to sol I guess its in order to display them in UI or console or to calculate them in an env which uses the sol measurment instead of the Lamports used to comunicate with the network itself.