The need to put large numbers into perspective is important for wise decisions affecting the well being of society and the health of democracy. The reason is that important judgements affecting public policy must be made by ordinary people and their elected representatives, judgements based on facts often presented using very large numbers, the sizes of which make it difficult for us to understand. The purpose here is to discuss the problem of understanding, relating to, and possibly visualizing large numbers. Large numbers may be categorized as what I call pure numbers and those used to characterize real things. The pure numbers are not intended to represent any things in particular, or numbers of things. The largest known prime number is an example of a pure number. It is a very big number, but it is probably of interest and direct relevance to few major policy decisions. Our attention here is directed exclusively toward the other kind of numbers, numbers with units or physical objects attached to them, such as dollars, people, years, stars in the sky, and distances, areas, and volumes.