And here are the two differences I think your expression is hitting on:

    Expression: 750/300
    Python 2.7: 2
    Python 3.9: 2.5
    C: 2.000000
    SQLite: 2
    Node: 2.5
    Java: 2
    Go: 2

    Expression: -123%10
    Python 2.7: 7
    Python 3.9: 7
    C: -3.000000
    SQLite: -3
    Node: -3
    Java: -3
    Go: -3

There might be more. Though, there's a ton of needless obfuscation in your expression.