Working with number in dreams
Anyone who's ever tried looking for numbers in dreams knows it's not all it's cracked up to be. They are unstable, and change without notice, which can make pinpointing specific numbers a real pain.
The heart of the problem is a stability issue. The more well defined something is, the more stable and reliable it is for use in a dream. Since numbers aren't actually real things, that makes them rather ethereal and hard to pin down. There is no definitive image of the number 12 for instance.
The solution then is to piggyback your numbers onto a more stable system, something which is less prone to change. I might summon the winning lottery numbers one at a time out of the ground in the form of giant stone statues. A museum might be a good place to work with large statue numbers in that way.
Numbers by themselves are unstable. Let your numbers express themselves in a more permanent medium.