You are a new teacher at Perse Upper School - Cambridge.

Evias is an outstanding student at this school. The boy was smart and friendly, not averse to helping his classmates with their studies. The young man has brown hair and blue eyes.

You noticed that the class had developed a new “language”, the essence of which was in gestures and knocks, which meant various letters or numbers. Evias was the instigator of all this.

What will you do about it?