Large numbers are calculated by addition and decimals by subtraction. Solve a few more and solve a few less, and subtraction can solve them all. Skills: There are fewer math problems than Dobby, and all the big ones use drawing. Drawing is one of the best ways to help children understand problems. In the process of teaching children, parents can help them better understand the size by drawing line segments, shapes and even pictograms.

The problem of less than greater than less than can be summarized into the following three categories:

One is to ask more questions and ask less questions: for example, there are 39 Xiaoming and 23 florets. How many florets are less than Xiaoming? (Or how many cards does Xiao Ming have more than Xiao Hua? )

The second is to find a large number: for example, Xiaoming has 39 cards, Xiaohua has more 12 cards than Xiaoming, and how many cards does Xiaohua have?

The third is to find the smaller number: if Xiaoming has 39 cards, Xiaohua is less than Xiaoming 12 cards, how many cards does Xiaohua have?

The key to solving the problem of finding a large number and a decimal number is to get a large number (large number) and a decimal number (decimal number) from the word "ratio". You can know who is older and who is younger by drawing, drawing lines, stick figures and drawing circles.