There are special tricks a teacher can introduce at the lesson, that may help for some time. BUT it's not the remedy and sooner or later they won't work too. In this case it would be a good idea to ask or help a more experienced colleague-teacher at your school.
Anyway, these tricks may help you for the start and can make your lessons more attractive for your younger pupils.

Here we go....
1. Bouncyballs.
It's a program in the internet that you can use to controll the limit of noise at the lesson. You will need a computer with internet connection and a microphone. The balls that you see in the picture start bouncing when the noise is increasing. So, the louder are the students, the quicker the balls are bouncing. You can change the theme from plastic ball that you can see in the picture to smilies, bubbles or eyeballs. It can work as a reminder for the pupils that it becomes noisy and they have to calm down.
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