The difficulty of mathematics in the third grade is basically equivalent to that in the fifth grade when I went to school in the 1980s, not only in mathematics, but also in other subjects. At present, there are many knowledge points of mathematical reasoning in grade three, and I have not learned them since 80 years ago.

There are five units in the first volume of mathematics in the third grade of primary school in the 1980 s, including: division of divisor is a single digit, mixed operation and application problems, preliminary understanding of decimals, addition and subtraction of rectangles and squares, and abacus calculation. On the whole, what they have learned is less than that in the current primary school mathematics textbooks.