The first medium Grade 1 sheet introduces the th digraph, which is trickier because it has two versions: voiceless (thin, bath) and voiced (that, them). Nine fill-in-the-blank sentences cover thin, that, them, thick, thank, with, bath, this, and brother, showing th in initial, middle, and final positions. A four-pair matching activity then sorts th examples by position and voicing, helping first graders hear the subtle difference between the two th sounds.