Again line 64 is the total of W-2 and 1099 withholding that comes from the Tax Payments Worksheet line 20 that is adding lines 10-19 each of which is a whole number that has been rounded to the nearest dollar per IRS instructions. There is no problem if it is not the same if you add it yourself without rounding.
It is not anything that I would worry about at all. The IRS usually ignores any errors do to rounding and would not bother for $4.00. The postage to amend (with tracking as all mail to the IRS should have) would cost much more than any additional tax or refund.
Any math errors that the IRS might find on a 2016 tax return would have already resulted in an IRS letter.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
