In the second unit, I learned how to calculate the addition and subtraction within 10 thousand. For example, in the process of writing a vertical body, pay attention to the alignment of numbers, and don't forget to write the answer in a horizontal body. Horizontal lines should be drawn with a ruler, and addition should not be regarded as subtraction. Where the digits add up to ten, you should enter 1. Where the number of digits is not reduced enough, you must borrow ten from the previous digit. In addition, in this unit, I also studied calculus. For example, my mother bought me a dress and a pair of sports shoes, a dress 135 yuan and a pair of sports shoes 48 yuan. Mom gave money to Aunt 200 yuan, and Aunt gave it to her 17 yuan. Small change, right? It's no problem to pass calculus. You see, mathematics is also very useful in life! I must learn math well.