Is null considered zero and undefined not a number on arithmetic expressions?

Question

Is null evaluated to 0 and undefined to NaN on arithmetic expressions?

According to some testing it seems so:

Answer 1

It seems safe to assume so since, in an arithmetic expression (e.g. addition), the method ToNumber would be called on it, evaluating NaN and +0 from undefined and null respectively:

                     To Number Conversions
╔═══════════════╦════════════════════════════════════════════╗
║ Argument Type ║                   Result                   ║
╠═══════════════╬════════════════════════════════════════════╣
║ Undefined     ║ NaN                                        ║
║               ║                                            ║
║ Null          ║ +0                                         ║
║               ║                                            ║
║ Boolean       ║ The result is 1 if the argument is true.   ║
║               ║ The result is +0 if the argument is false. ║
║               ║                                            ║
║ Number        ║ The result equals the input argument (no   ║
║               ║ conversion).                               ║
║               ║                                            ║
║ String        ║ See grammar and note below.                ║
║               ║                                            ║
║ Object        ║ Apply the following steps:                 ║
║               ║   1. Let primValue be ToPrimitive(input    ║
║               ║      argument, hint Number).               ║
║               ║   2. Return ToNumber(primValue).           ║
╚═══════════════╩════════════════════════════════════════════╝

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