Don't these look like fairy breads?
Learning about halves is quite hands on as there are many things that could be halved: playdough, unifix cubes, symmetrical shapes, fairy bread, pizza, fruit.
Children will know about half before they enter school as they use it in their everyday life. They know when something is not shared equally. The important point to teach children is that half means that both things are the same.
For the activity above and below, I had the children fold the shapes in half first. They had to make sure that both sides are the same. They then cut. As you can see some of the pieces are not exactly the same - this is more a problem of cutting!