Mathematical thinking means that teachers guide students to visualize mathematics and form mathematical operations according to mathematical materials in teaching activities. That is what we often say to cultivate students' "sense of numbers". For example, there are 20 birds, and 5 birds fly in. This is mathematical material; Mathematical operations based on these materials are mathematical thinking. For example, there are eight birds, and four of them fly in. How many are there in a * * *? Eight birds and four more flew in. How much did you fly less? There used to be eight birds, and then four flew in. How many times did the original fly?