Hong Jinsong draws inferences from others. According to relevant data, Hong Jinsong's "Primary School Mathematical Thinking Development Course" can effectively cultivate children's reaction ability and example level, covering all the questions of primary school thinking training. The third grade mainly includes filling operation symbols, addition and subtraction, sum and difference problems, logical reasoning, sum and multi-problems, difference and multi-problems, filling and defining new operations, square matrix and age, skillfully calculating perimeter, set, reasonable arrangement and pigeon's nest principle, reduction and elimination, division of divisor into single digits, periodic problems, tree planting problems, slightly complicated sum and multi-problems, multiplication of two digits by two digits, arithmetic series and so on.