Using GIMP 2.8.22, Making "lossy-ness" around smaller images disappear

[Ofnuts]

Nothing much to do except erasing by hand around the numbers.

But IMHO you can:

1. create the letters, numbers and +/- signs from scratch using the text tool and an adequate font.
   
2. Find  a better image for the notes, google for a lossless format such as PNG
   
3. Find better images for pencil/brush (look for "clipart")
   
4. Do the mouth using a vertical ellipse selection, from which you delete and horizontal ellipse selection