If the federal tax for the year is less than $1,000 there is no need to have any withholding at all. The person can simply pay the total tax when he files his tax return. There will be no penalty if the amount owed is less than $1,000. With such low pay, employers will probably not withhold any federal tax. So just answer the questions on Form W-4 accurately and don't worry about it. For such small amounts it's not worth putting any effort into trying to manipulate the withholding.
Also keep in mind what I said earlier: you cannot legally claim exemption from withholding on the W-4 if you will have to pay any tax at all for the year, even if the tax is only a few dollars.
