Brief introduction of My Beautiful Ruler: unit of length and measurement: In this series, children's understanding of measurement concepts and tools is deepened by comparing the sizes of different things, measuring with their bodies, understanding money, observing time and understanding the uniqueness of the concept of time. What is a math picture book? Picture book: Very nice. Some of its pictures are wet, some are warm, some are lifelike, some travel through time and space to the soul, some are precise and rigorous, and some are simply photos. It tells stories and only looks at pictures, so that young minds can feel the beauty and beauty of the world.