I left the Post in 2008. I haven't talked to anyone there since completing my training. I don't even know who works there anymore. I know nothing about what they're doing, and I have no opinion whatsoever to share.
Do you mean adult math? What you should know is I didn't get to learn college-level math or its equivalent. Now that I'm exposed to data science, coding, etc. I found that learning these things did not make me exceptionally good at math either. But knowing just enough math can really be beneficial for things like the rule of thirds for photography, the golden ratio for web design, and to produce better-looking curves in your designs.
Filing a PPh 21 income tax is the responsibility of the employer. As a freelancer, or a non-employee individual to your company, I expect to receive my payment in full. You should calculate the income tax based on my fee but not as a deduction, and I am entitled to a copy of the tax receipt you filed. Also, please be aware that PPh 21 for non-employees only applies if my total income from you reaches IDR4,500,000 (US$311) per month or IDR450,000 (US$31.1) per day for an entire month. The 2% PPh 23 withholding service income tax will automatically apply to my service fee if it is eligible for a PPh 21 filing and after the income tax is filed—only if the work does not come with a service agreement or contract.
Although I can draft you general contracts or standard agreements for a fee, I am not a practicing advocate or a consultant in the field of law. This means that I will not be providing you with advanced advice needed to cater to your very specific legal needs, and because I currently prioritize in servicing English-based projects, there might also be an added translation fee to have the documents translated to bahasa.
You can consult with me prior to applying for a foreign EIN, but I won't act as a third-party agent or apply for the employer identification numbers on your behalf.
My rates take into account the time available to work on the tasks. There is an extra rush fee for rushed work, which also applies to weekends. So don't worry, we'll get things done in time.