I would recommend just going with the value you are given which is closest. Thus, for P(Z < 1.212) just use the given precision you know: P(Z < 1.21).
I need a clarification before my S2 exam on Thursday. How do I find a value of P(Z<0.7925)? This is bearing mind that all the table values are to 2 decimal places. Previously, I have compare it to the closest value and then subtract to get my final result. For example, if I need P(Z<1.212), I would compare it to P(Z<1.21) and P(Z<1.22). Since it is closer to 1.21, I would subtract .002 from the table value. Is this method correct? I am getting a slightly different result to the questions. Please help.