The point is that '1e' is not a valid number in Perl, so your answer of 7 is at best flawed.
C:\test>perl -Mstrict -wE"say 0+'1e'" Argument "1e" isn't numeric in addition (+) at -e line 1. 1
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.