My mathematics teacher

[Bassim]

Would you please correct the mistakes in my sentences?

My mathematics teacher had an effective method to impose discipline in the classroom. If he heard a couple of students chatting during his lesson, he would snap the chalk in two and hurl the pieces at the disruptive couple. He would usually miss, but that taught them a lesson.

 

[jutfrank]

I can't see anything I'd call a mistake.

 

[teechar]

My mathematics teacher had an effective method of imposing discipline in the classroom. If he heard (any) students chatting during his lesson, he would snap the chalk in two and hurl the pieces at the disruptive students. He would usually miss, but that taught them a lesson.

I would make the above changes.

 

[emsr2d2]

Although we use "a couple of" to mean "two", generally the word "couple" denotes two people in a romantic/intimate relationship.

 

[bubbha]

I would use "pair" instead of "couple".