## Do Yourself a Favor

For a chronological index of my path to the CFA, click here.

Just a quick suggestion today to do yourself a favor and go through your calculator manual to really learn all of its financial functions before you get too far into the CFA study guides.

After breezing through Ethics & GIPS, I made the mistake of starting on the problems in the Time Value of Money (TVM) chapter in Volume 1 without doing so.

This turned out to be a big time-waster because the 12C has all sorts of short-cut functions that save you from having to write down formulas on scratch paper, manipulate with algebra to solve for your variable of interest, and then plug-and-chug with the calculator.

One thing I really wasted time on was not knowing about the BEG and END buttons.

These are useful if you’re making annuity computations but in some cases payments start at the beginning (BEG) of each period and in other cases at the end (END).

I learned enough to know that the 12C could do it one way, but thought it was the only way.

So when payments happened the other way around, I had to do little tricks like leave off one of the payments & then add it back at the end to get the right answer.

Painful and easy to mess up…

Once I discovered BEG / END I went back and re-worked the TVM problems at lightning speed (well, maybe not lightning, but much faster).

This left me wondering if, for speed on the CFA exam, it’s even worth knowing how to derive & manipulate all the different TVM formulae when the 12C just gives you the answers much faster?

The CFA study guide doesn’t always present complete derivations of formulae anyway. In the section on ordinary annuities, they start off with one equation:

FVN = A * [(1+r)N-1 + (1+r)N-2 + … + (1+r)0]

and then they say that it “simplifies to” a second shorter equation:

FVN = A * [((1+r)N – 1) / r]

with no mention of how they got there (multiply both sides by (1 – r) as shown here).

In addition to working through your calculator manual, if you’re using the 12C I’d highly recommend TVMCalcs.com’s HP 12C Tutorial.

I haven’t worked through the entire thing yet, but here are two helpful bits I came across:

1. Perpetuities: The 12C can’t really do a perpetuity, in the sense that you can’t enter infinity for the payment period (n). But you can do perpetuity calculations by using the same functions used for annuities, with n set to a large number. See TVMCalcs.com’s Example 2.6.
2. Solving for n: Perhaps answering my earlier question about how much knowledge of formulae is required, I found a case where the 12C actually gives the wrong answer. Briefly, if you enter a present value, desired future value, and interest rate and tell the 12C to solve for n, the 12C always returns an integer. See TVMCalcs.com’s Example 1.2. If you’re using a 12C, be sure you know about this.

I don’t know yet whether I’m relying too much on the old 12C – it seems like it’s doing most of the heavy lifting. But the practice problems at the end of the section will give insight into whether this is how it’s supposed to be.