You could use Conditional Formatting to do that (say, hide all instances of 0 by coloring it to match the background). To hide all numbers or a range of numbers, just make the conditional formatting cover the whole range.
One caveat: If someone highlights the cells (say, with a mouse), the data will show up--dim, but perfectly clear. Two caveat: If someone prints the spreadsheet with print settings set to Black and White, those numbers will print out the same as any other number (Page Setup, Sheet tab, Black and white).