What if Everybody Did That? by Ellen Javernick This one should come standard with every primary classroom. The book goes through a day with a little one who does things without thinking, like feeding zoo animals despite the warning signs not to. He's got that same feeling that lots of kids do - that their actions won't make that big of a difference. But the community helpers in this book get him to think of what would happen if everybody did that.
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What if Everybody Did That?: A good book to teach the need for rules and how our actions have consequences
First day class rules: I actually have this taped to the inside of my classroom door. After my students see these (and chuckle a little), my rules don't seem so bad.
In The Town All Year 'Round - this is BY far the most favorite book in our house. My 6 year old still loves it and my 3 year old reads it every single night.