4. Blue part of eraser
The blue part of your eraser has its own value. It is used to scratch out the markings from thick paper. It doesn’t leave any trace of award that was written there.
5. Horizontal buttonholes
You would’ve noticed the difference between the uppermost buttonhole and other buttonholes. The reason behind this is the uppermost button is more likely to undone easily. Therefore, it becomes necessary to provide horizontal buttonhole.