1. Create situations, experience values and form estimation consciousness. There are many things in life that don't need accurate calculation, just estimate them, such as shopping in the streets, shopping and traveling abroad.

2. Teach methods, make reasonable choices and master estimation skills (as mentioned in the above experience).

3. Consciously apply, serve life and solve practical problems. Mathematics comes from life and serves life. The main purpose of cultivating students' estimation ability is to let them solve problems in life. Practice shows that the closer mathematics is to life, the easier it is for students' emotions to cause * * * sounds, which is also an aspect that can not be ignored in estimation teaching. Estimation teaching is not independent, and should be closely linked with practice.

① When you and your family go to a restaurant for dinner, participate in checking the names of dishes and the corresponding prices, and estimate the total price. Finally, the accuracy of the evaluation is compared with the list provided by the service desk. It is suggested that math diary communicate with classmates.

② The school organizes spring outing and participates in designing consumption plan;

(3) as the "chief financial officer of the family" and count the income and expenditure of the family for one month;

(4) Estimate the number of books on family shelves or books in school libraries;

⑤ If a classmate saves one grain of rice a day, how many meters can the whole school save a year;

⑥ Estimate the number of words in the newspaper layout.