There are two themes of interest for children in this surah: the manner and scope of creation and the story of Ibrahim (a). If you would like to read the story of Ibrahim (a) to your children there is a chapter concerning him in My Little Lore of Light by Hajjah Amina Adil:
In this surah it says that Ibrahim (a) destroyed the idols. When his people suspected him Ibrahim (a) told them that the largest idol had destroyed them and they should ask the idol. They told him that the idols do not speak. Ibrahim (a) was later thrown into the fire and found it cool.
Discussion question: when Ibrahim (a) destroyed the idols what was he trying to teach his people? Why was the fire cool for Ibrahim (a)?
This surah mentions that living things are made from water and that creation will roll up like a scroll and then another creation will be produced. I think that for this lesson I will play the video Powers of Ten to give an idea of the scope of the known universe:
Discussion question: why is water important for life? What is the purpose of the creation? Why is there more than one creation?
Image: this is a drawing based on a stone carving of the tree of life. I have adapted the image to represent the tree of prophets with their lights in gold.