1. Mixed operation of fractions and decimals: This kind of problem usually involves the mixed operation of addition, subtraction, multiplication and division of fractions, decimals and percentages, which requires students to master the transformation law between fractions and decimals and the order of the four operations.
2. Geometric problems: These problems involve the properties of plane geometry (such as triangle, rectangle, trapezoid, etc.) and the application of calculation methods. Students need to have strong spatial imagination and logical reasoning ability.
3. Proportion and similarity problem: This kind of problem requires students to find out the relationship between two or more quantities according to the known conditions, and solve the unknown quantity by using the proportional relationship or the properties of similar triangles. This requires students to have strong analytical and computational skills.
4. Logical reasoning questions: These questions usually contain some conditions and conclusions, which require students to use logical thinking ability to infer correct conclusions from given information. For example, given a group number, students need to find a combination that conforms to certain rules.
5. Solving equations: This kind of problem requires students to solve equations according to known conditions, and solve the equations to find the unknown quantity. This requires students' thinking ability and computing ability.
It should be noted that students of different grades may face different challenges. As students gradually adapt to the learning content and difficulty of primary school mathematics, they will be able to better cope with these problems.