Typical application problems in grades 3 and 4 mainly focus on problems such as sum and difference times, reduction, overlap, profit and loss problem, sharing a cage with chickens and rabbits, and preliminary itinerary. Learning the following five methods well can help us solve these problems quickly.

1. graphic method: concretize abstract mathematical problems, solve mathematical problems through graphics, and exercise the idea of combining numbers with shapes.

2. Reduction method: knowing the conditions of backward deduction of results, training students' reasoning ability and backward thinking ability through tables, line segments and process diagrams.

3. Elimination method: The idea of "binary linear equation" eliminates an unknown condition through two equal relations and exercises students' reduced thinking. ? 4. Hypothetical method: A typical chicken and rabbit cage problem, through hypothetical thinking, bid farewell to complex enumeration, so as to solve problems faster and exercise students' hypothetical thinking.

5. Comparative method: By comparing the similarities and differences of conditions, find out unknown conditions to solve problems and exercise students' comparative analysis ability.