Science is a way of understanding the world by asking questions and looking carefully for answers. Why does a boat float but a stone sink? Why does the sky turn orange at sunset? Why does a mango ripen faster in a paper bag? Every one of these questions can be studied with science. Science is not only a collection of facts in a book; it is a method of thinking. Scientists observe something, wonder about it, make a guess called a hypothesis, test the guess with an experiment, record what happens, and then decide whether the guess was right. If the guess was wrong, that is not a failure. It simply means a better idea is needed. Anyone can think like a scientist, and in Class 6 you begin to do it on purpose.
The three big branches you will meet are physics, chemistry and biology. Physics studies forces, motion, light, heat, magnets and electricity. Chemistry studies materials, what they are made of and how they change. Biology studies living things, from tiny bacteria to elephants and banyan trees. In real life the branches mix: when rice cooks, chemistry changes the starch, physics moves the heat, and biology explains why our bodies need the energy. Science also uses careful language. Instead of saying a stone is heavy, a scientist says its mass is 200 grams. Instead of saying water is hot, a scientist says its temperature is 80 degrees Celsius. Precise words and numbers let people in India, Thailand and anywhere else check each other. Throughout this course, every day ends with an activity, because science is something you do, not just something you read.
Example: Take a glass of water and drop in three objects one at a time: a coin, a small piece of wood and a plastic bottle cap. Before each drop, write your hypothesis: will it float or sink? Then test it and record the result in a table with columns for object, hypothesis, result and whether you were right. Expected result: the coin sinks, the wood and the bottle cap float. Finally write one new question the activity made you think of, such as why a heavy wooden log floats but a light coin sinks.