If the tax was 10%, then you’d end up paying the original 100% plus the additional 10% tax, so you’d pay 110% of the original price.
In your example, it’s the same, except you have 8.25% tax, so you’d pay 100%+8,25% or 108.25% of the original price.
That’s stated as a percent.
To convert a percent to a decimal, you divide by 100:
108.25 ÷ 100 = 1.0825
To convert a decimal to a fraction, you have to know the place value of the smallest place. In this case, the 5 is in the ten thousandths place.
10825/10000
You can always double check that fraction on a calculator.