Advisory story: You all laugh and criticize me for the one who made the mistake

One day the math professor wrote on the blackboard:

9×1 One day the math professor wrote on the blackboard 7
9×2 One day the math professor wrote on the blackboard 18
9×3 One day the math professor wrote on the blackboard 27
9×4 One day the math professor wrote on the blackboard 36
9×5 One day the math professor wrote on the blackboard 45
9×6 One day the math professor wrote on the blackboard 54

One day the math professor wrote on the blackboard.
– One day the math professor wrote on the blackboard? One day the math professor wrote on the blackboard.
– One day the math professor wrote on the blackboard, One day the math professor wrote on the blackboard.
– One day the math professor wrote on the blackboard, One day the math professor wrote on the blackboard, One day the math professor wrote on the blackboard.
– One day the math professor wrote on the blackboard…
– One day the math professor wrote on the blackboard, One day the math professor wrote on the blackboard. You all laugh and criticize me for the one who made the mistake.
– You all laugh and criticize me for the one who made the mistake. For, You all laugh and criticize me for the one who made the mistake. You all laugh and criticize me for the one who made the mistake.

Prim.dr.med.sc. Ali F. Elias