Calculus is a type of math that helps us understand things that are constantly changing. Think about a car driving - its speed isn't always the same, it changes. Calculus helps us figure out the exact speed at any single moment, and also helps us find the total distance traveled when speed is changing.
The first main idea in calculus is finding how fast things change. This is called finding the rate of change. It's like finding the slope of a line on a graph, but calculus can do it even when the line is curved. Watch how the slope changes as we move along this curve - the steepness is different at each point.
The second main idea in calculus is adding up tiny pieces to find total amounts. This is like finding the total distance you traveled if your speed was changing all the time. Instead of just multiplying a constant speed by time, calculus helps us add up all the tiny bits of distance. We can visualize this as finding the area under a curve by using many thin rectangles.
Calculus is used everywhere in the real world. In physics, it helps us understand motion and forces. Engineers use it to design safe bridges and buildings. Doctors use it to model how diseases spread or how medicines work in the body. Economists use it to find the best solutions to problems. Even computer graphics use calculus to create smooth, realistic animations.
Don't worry about learning complex formulas right now! As a 7th grader, the most important thing is understanding the big ideas. Calculus is basically the math of change and motion. Remember these two main concepts: finding how fast things change, and adding up tiny pieces to find totals. You'll learn all the detailed methods in high school and college. For now, just appreciate that calculus helps us understand our changing world!