My son is in 1st grade. They have those cube things too.
Most classes have that.
And sure, some kids may take it.
What my son's Teacher does, if the scenario involves "stealing" and "lying"... the Teacher, makes a pointed discussion with the kids. About it.
And, she is blunt and articulate in her speech to them.
It also means, that all the money that the Teacher spends on her classroom FOR her students, gets, "stolen" too.
Another point is: it is NOT kind nor nice not fair, to the other kids. Because, that child is taking.... classroom materials, etc.
And my son's Teacher, talks directly to the student who did it too. And it may involve, doing it in front of the other kids (without singling out the child) in a "kind" but direct manner. Or it may be done privately, between the Teacher and child. Depending on the personality of the child, and what will hit home, the best.
I would have, with my kid, went to the Teacher and have my child, give it back/apologize to the Teacher, and take whatever consequence the Teacher decides. And your child needs to TELL the Teacher, that she took it when she was not looking.
The Teacher, needs to know, this.
Your talking to your child about this, is not working.
She still does it and keeps doing it.
For some kids, being found out, by the other kids and the Teacher, will nip it. Because then, she is not doing it in a vacuum. Still in "secret."
Then, she is not the first one to take these cubes home.
The Teacher knows that.
Still, it is not nice nor honest.
And if every kid took things home from the classroom, the Teacher is the one that is suffering for it, too.
Tell your daughter, it affects her Teacher.
The Teacher works hard... to buy and provide things for her classroom and for the students. There needs to be respect, for that.
And instead of teaching her the right/wrong of it... you ALSO need to teach her, that things like this affects... others, too.
It is not just her, doing something for herself.
It affects, others.
And that, is not nice. To say the least.
My son's Teacher, will tell the child, that she is very "disappointed" in him/her. And that it makes her sad. And that, it affects her classroom and the other kids. Now, they don't have what they need. Now, things are missing etc. And the child needs to learn... that things like this, affects... others. In a very disappointing, way.
It is not just about trust. But more than that.