Rounding

Hello Sir,

Question 29 of the Acca FM specimen exam

The question asks us to calculate the expected Net present value. The EV is $26,500 which I had calculated correctly.
However, to discount it I multiplied by discount factor directly in my calculator (1+12%)^-3. The answer comes out to be $18,862.
The examiner has done this using the tables and has gotten the answer of $18,868.

This seems like a large discrepancy, and I wanted to ask in such a situation what do I use, the tables or the direct discount factor?

And to Clear up I was doing the exam on their CBE practice platform and their marking tool marked my answer incorrectly.