Okay so if your dividing by eighths then the fraction would be 1/8 and to draw it you would draw 7 lines for 8 parts (I’m not sure if this is what you were asking)
First draw a line in the middle of your box vertically. Then draw a horizontal line that is also in the middle of your box and then draw another line above the horizontal line and below the horizontal line in between the two boxes you made I added a picture below to show. The fraction is 1/8
