Algorithm design. The most difficult thing to understand in the new mathematics curriculum standard is algorithm design. The difference between the algorithm and the usual problem-solving is that the problem-solving does not necessarily have strict procedures, but it must be carried out in strict accordance with the steps if it is to be executed by a computer. Therefore, in the algorithm design, we should think clearly at every step when solving problems, which is a great test for students' logical thinking ability. The diversity of algorithms and the optimization of methods will also make students uncomfortable.