You must have DEEP ROCK and BLUE GLASS BLOCK to make NUMBER. NUMBER is in wallpapers category. Better plant this and come back later, it takes some time. Breaking this block will give you 5 experience points. NUMBER can be broken. Seed mathematics is very complicated, but you should get at least 1 seed back from splicing NUMBER. Will you strike it rich? You just have to count the gems yourself. Massproducing NUMBER can be tricky. You will find out after you have harvested a few.