Sagemath is a thing like a magic notebook that helps you do lots of different math problems. You can type in numbers, formulas, and other math things into the notebook, and it will give you answers and show you how it did the math.
It's kind of like having a really smart friend who knows a lot about math and can help you solve problems. But instead of a real person, it's a computer program.
The program also has some cool features like drawing graphs and creating 3D shapes, which can help you understand math better. Overall, Sagemath is a helpful tool for students and researchers who need to do advanced math quickly and easily.