Worksheetworks is another site where you can find free worksheets to print. What makes this site different though is that you can customize the worksheet to suit your students age and ability and the site will generate a worksheet for you which you can download as a PDF. The worksheets found on this site are also of higher quality and are not (much) boring like the average worksheet. For example take a look at this Addition maze or Addition Problem Search where students have to find addition problems like a word search. All worksheets are provided with an answer key. There are also worksheets for grammar and literacy, puzzles, maps and some other misc worksheets.