What Watermom is trying to say is that FC (free chlorine) + CC (combined chlorine) = TC (total chlorine). Combined chlorine is USED UP chlorine--you want this reading to be 0.

FC (5) + CC (0) = TC (5) --> Here, all the chlorine is Free chlorine sanitizing your pool.

However, if FC is (2) and the CC is (3), your TC would still be 5:

FC (2) + CC (3) = TC (5) --> In this scenario, you would have more combined chlorine in your pool than free chlorine.

Although I've never seen a 'tablet drop' test that you have, I'm pretty sure it won't measure the FC and CC separately; therefore, you are getting a TC reading. A good test kit, as previously mentioned, will provide you with these separate readings and save you a lot of confusion.

Hope this helps!
Chris