Principles and standards for school mathematics have been set forth by the

National Council of Teachers of Mathematics (NCTM). These standards emphasize the importance of developing students' mathematical understanding, proficiency, reasoning, and problem-solving skills. Some of the key principles and standards outlined by the NCTM include:

- Students should have a deep understanding of mathematical concepts and procedures, rather than just memorizing procedures.
- Students should be able to apply mathematical concepts and skills to solve real-world problems.
- Students should be able to communicate and justify their mathematical thinking and reasoning.
- Students should develop their mathematical reasoning skills, including the ability to make conjectures, construct arguments, and evaluate the validity of mathematical statements.
- Students should use technology as a tool for learning and solving mathematical problems.
- Teachers should create a classroom environment that supports the development of students' mathematical understanding and reasoning.

Overall, the NCTM principles and standards for school mathematics aim to ensure that all students have the mathematical knowledge and skills they need to be successful in today's world.