Second and third grade students created illusion art. They had to measure a section of paper horizontally and then fold the paper so that each section was the same size. Then they counted how many sections there were to draw in. They knew that they were having to draw 2 pictures, so they had to divide the number of sections by 2 to figure out how many sections they had for each picture. Then they thought of an image, drew it on practice paper, and then drew dividing lines so that they could see what needed to be draw in every other section. They repeated that for the next picture. They looked down the paper to see that their lines matched up and then if so, colored. So if you look one way its one image and then when you look the other way its a different image.