I've seen that on Pinterest. I love that project! If I didn't have a Silhouette I'd probably make it with stickers and Mod Podge. Or print it on paper and put it in a frame. All those numbers would be time consuming to hand cut. If you want, email me at firstname.lastname@example.org and maybe I can help.
When you cut the vinyl you have to peel away the excess vinyl (so you just leave the image you want). With lettering it takes a long time because there are so many small pieces. It's not hard, just time consuming.