Aphorism #43 is a critical aphorism, especially the last section of this aphorism. If you become comfortable with #43, if you can talk about meaning in these terms, then you will have understood something quite central for all of Wittgenstein's philosophy.
Here is #43:
the call "block" to get the worker to fetch a block (that was the use of this call "block!" in language game #2). In another language game we might imagine that the call "block" was meant to get the worker to put the block behind the fence. But in language game #2 it meant "fetch me a block."
Now, imagine some confusion of the worker: The worker doesn't know what to do when the supervisor calls out "block." What is the source of this confusion? Is it because the worker doesn't know what a block is? Maybe. Or is it that the worker knows exactly what a block is, but he sometimes plays the language game of putting them behind the fence and now the worker doesn't know what to do to comply with the supervisor's call. In first case, the supervisor might explain his meaning by walking over (Augustine style) and pointing to the pile of blocks. (This is the case that LW mentions at the end of aphorism #43.) In the second case, however, which is the more more common kind of confusion, the worker doesn't know what to do with the block. He knows what a block is, but he doesn't know to fetch it. (This is the case LW mentions in the first part of aphorism #43.) If the confusion is about what to do with the block, the supervisor will need to show the worker what the use of this term is in the language game. The supervisor will need to show the worker how to fetch -- because that is the use of the term "block" in language game #2. That is how the term is being used. Or in other words, in language game #2, the call "block" means the worker should fetch a block.
This analysis has relevance for our lives. In many situations in life, we know what people are referring to, but we do not know the language game they are playing -- we do not know the use (or meaning) of the terms in the language game. Someone says, "Nice tie," and what is the use of this statement in the language game? Is it meant to butter you up? Is it meant to get you to give them your tie? Most of the time when you wonder what people "mean" you are wondering how they are using terms. Someone says, "yes," after everything they say. What do they mean by that? Do they mean they agree with you? Do they mean they understand you? In these examples you will need to know the use of the word "yes" in the language game being played.
Now, suppose you are in a store in a foreign country shopping for small objects. You speak the foreign language in a very clumsy way and often have to have meanings explained to you. You go up to the shopkeeper with a small statue of a bird and you say the foreign language equivalent of, "How much is this?" The shopkeeper gives you a one term reply that is the price. You know that you have been given the price, but you don't know exactly what that means in this context. In some contexts, you know, a priceis not a non-negotiable. But in others it is simply a bargaining ploy. Your question here about meaning has to do with the use of the "price" in the language game. If you want to know what he means by the price, then you need to know if this is a final amount or if he is negotiating -- for these are two different language games. The Augustinian approach to explaining meaning would have you pointing at the paper and coined money on the counter and saying "ten dollars." Sometimes that is what we need, but not usually. Usually we want to know how the term is being used in the language game. And it is this dimension of meaning that Wittgenstein is calling attention to in #43.