Your problem does not indicate using the percent format, or at least that is not indicated here. But the wording "portion" seems like we should.
When a word problem is worded "____ out of ____" we express it like this:
51/64 - this indicates 51 divided by 64
Giving us 0.796875
Move the decimal two places to the right to change it to percent.
79.6875
Now round the 7 up to 8
79.688%
IF you do not feel this should be a percent answer - revert back to the original quotient - 0.796875 and round the 6 to a 7 giving you .797 - but that doesn't make much sense to say that you got .797.
