DOUBLE TAP TO ZOOM WITH PHONE OR TABLET themselves become the focus of experimenta- tion. Technology, therefore, serves two purposes in the early childhood curriculum. First, it can enhance scientific learning by expanding oppor- tunities to observe and experiment. Second, chil- dren can study the technology itself to enhance their understanding of science. Children may also use technology as part of the mathematics curriculum, particularly in the area of measurement. Balance scales, thermome- ters, wind wheels, weather vanes, measuring cups and spoons, and timers (particularly the hour- glass styles in which falling sand marks elapsed time) are examples of appropriate technology for early childhood mathematics investigations. In addition, items such as kaleidoscopes and mirrors can help children create symmetrical images. Connections to engineering were presented previously in this chapter. Children learn about engineering through their exploration of mate- rials, such as building with blocks, experiment- ing with solid and liquid materials, and adhering materials with glue, tape, staples, twine, and even nails. In addition, the objects that children use in these explorations (from various shapes of blocks to boxes and paper rolls) strongly support geom- etry. Shape and position are critical components of building stability. Although science and mathematics have nat- ural connections in the curriculum, children’s learning mechanisms in these two disciplines are somewhat different. Piaget’s (1971) framework of three types of knowledge can help teachers un- derstand how learning occurs in science and mathematics. The first type of knowledge, physical knowledge, encompasses the physical properties of objects, such as color, texture, temperature, weight, and shape. Children discover these prop- erties by interacting with objects, manipulating them, and observing the results. Conceptual un- derstanding of the physical properties of materi- als comes from this direct interaction, not from reading or being told about them. For example, children learn that coldness is a property of ice by touching it. They observe that ice begins to melt and turn to water as they hold it in their warm 10 c ha p te r 1 hands. This type of experience is the essence of physical knowledge. Much of science involves un- derstanding the physical properties of objects, as well as manipulating materials and observing the results. Most scientific learning, particularly for young children, involves physical knowledge. The second type of knowledge is logical- mathematical knowledge, which is constructed in- ternally by the child. Children form all kinds of relationships based on their experiences— numeric, similar/different/same/opposite, more/ less/same, symmetrical/asymmetrical, difficult/ easy, and so forth. All of this knowledge resides inside the child rather than within the proper- ties of objects or experiences. For example, there is nothing about a truck and a car that makes them similar until an individual decides they are closely related, perhaps because both have wheels and are used for transportation. Another person might determine that the same two ob- jects are different because the truck is larger and is used to carry cargo. Since virtually all of mathematics involves the formation of relation- ships, learning in mathematics centers around logical-mathematical knowledge. Although physical knowledge and logical- mathematical knowledge are different, they often occur almost simultaneously as children learn. It is through their experiences with objects that children discover characteristics that they use to form relationships. By lifting a ball and a balloon, children discover that one is heavier than the other, a logical-mathematical relation- ship that is constructed after children discover a physical property of the two objects. By grouping shells and pebbles into two categories based on their physical characteristics, children may dis- cover that there are more shells than pebbles. In this case, the physical properties of the shells and pebbles provide a context for making a numeric comparison. The third type of knowledge in Piaget’s frame- work is social knowledge, information agreed upon by cultural groups. Manners, rules, vocab- ulary, and customs are examples of this type of knowledge. The only way children can learn this COPYRIGHTED MATERIAL