The word "solution" should be written at the beginning. If it is proof, write "proof". There is generally no need to write "a". It seems that all primary school application questions are required to be written, but the word "A" is written in the application questions to indicate the conclusion, so the format is clearer. Proof questions generally use "∴" as the symbol before the conclusion.

In primary school mathematics, practical problems with quantitative relations are described by language or words, and the problems formed in this way are called application problems. Any application problem contains two parts. The first part is known conditions (conditions for short), and the second part is seeking problems (problems for short). The conditions and problems of application questions constitute the structure of application questions.

Mathematics application problems in primary schools are usually divided into two categories: simple application problems that can be solved in one step only by addition, subtraction, multiplication and division; Complex application problems that need two or more operations to solve.