Calculus is an important mathematical subject, involving functions, limits, derivatives, integrals and other concepts. To learn calculus scientifically and systematically, you can follow the following steps:

1. Establish a mathematical foundation: Calculus needs a certain mathematical foundation, including algebra, geometry and trigonometry. So, before you start studying calculus, you should master these basic knowledge.

2. Learning limit: limit is one of the basic concepts of calculus. You can learn the definition, nature and application of limit by reading textbooks or taking classes.

3. Learn derivative: derivative is a concept that describes the rate of change of a function. You can learn the definition, nature and application of derivatives by reading textbooks or taking classes.

4. Learning integration: integration is a concept that describes the area or volume of a function. You can learn the definition, nature and application of integral by reading textbooks or taking classes.

5. Exercise topic: Consolidate what you have learned and improve your problem-solving ability by doing problems. You can start with simple topics and gradually increase the difficulty.

6. Seek help: If you encounter difficulties in the learning process, you can seek help from teachers, classmates or online resources.

7. Summary: In the process of learning, we should constantly summarize and summarize what we have learned and form our own mind map or notes.