Last year, Teacher Shuru conducted an open class on "Surface Area of a Cube" in fifth-grade mathematics. She used soap boxes, toothpaste boxes, and other boxes that are easily collected in life to teach fifth-grade students the calculation of surface area. In the past two years, the school has been evaluating the possibility of "building a secret base - building a tree house with children", and finally decided to officially launch it in the next semester. Therefore, we will first conduct the precursor course of the tree house this semester, through Indoor space design, learning model making, practicing scale conversion, cultivating a sense of length and volume, and also improving schoolchildren's knowledge related to space planning, space layout and life aesthetics.