A common use of numbers is to indicate you at a particular age. This may be obvious if the dream has, for example, a 3 year old child in it. A less obvious symbol is the use of a number of people. For example, a dream with 2 women behind you is introducing an issue with mother when you were 2 years old. A dream with 7 children playing together brings you back to the age 7, and so on.
Numbers can also indicate the need to put energy into developing an aspect of you when they are part of a price tag. For example, $3 for a pen asks you to commit (3) to developing your writing ability. Price tags can also indicate reward for development. Being offered $600,000 to work in the music industry tells you there will be great reward from developing your channeling ability (music).
For the meaning of specific numbers lookup the individual numbers that form it in this reference.