Well if the information is so important than why don't you email the students and cc the parents at the same time. This has been done in my school and is very effective. We also use the call system through the school, the teacher does not have to make personal phone calls on their own time, it is a system the school uses.
Sorry but I do not feel texting students is appropriate, it leaves parents out of the loop, and yes there are a lot of parents that should be more involved in their children's activities but if you are texting the children and not emailing or calling or coding in the parent how are they even supposed to know what is going on.
This needs to become a county wide issue where all schools notify parents and students in the same manner. There are to many students who are to vunerable to adults who pay attention to them, especially when it is when it is someone they look up to and trust.
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