Place numbers on flat surface with the two end pieces on either side. Line them up straight and put masking tape over the face to keep them together.

Draw a straight line with a level where you want the numbers to go.

Place the numbers on the wall (or desired location) and mark the outlines of the mosaic numbers. Then lightly scrape and sand that area. Clean any residual dust.

Flip numbers over carefully. Apply Liquid Nails Marble & Granite Poly Adhesive on the back side, available at Home Depot.

Place the lines of the glue close to each other like in picture above. This will ensure that all the small pieces will stay together and adhere to the surface.

Place the numbers on the wall; make sure it is in the spot marked before. Press all the sections firmly and evenly to the surface. Clean any excess glue from sides. Put the masking tape on the numbers and the wall to hold them securely in place while they dry. And let dry for 24 hour.

Mix desired grout color with water to a peanut butter consistency. Spread it on the numbers so it fills all the joints between the pieces, on the face and sides. Let sit for 10 minutes.

After 10 minutes. Clean all excess grout with a damp sponge. Rinse sponge in Bucket half filled with water when it gets dirty. Make sure all joints are grouted.

Let dry for one hour and clean gently with a dry cloth. And let dry for 24 hour.