Bài 9:viết số lớn nhất và nhỏ nhất bằng cách dùng cả 10 chữ số khác nhau(mỗi số chỉ được viết 1 lần) Bài 12: Tính các số tự nhiên chẵn có 4 chữ số Bài 13:muốn viết tất cả các số tự nhiên từ 100 đến 999 phải dùng bao nhiêu chữ số 9

Các câu hỏi liên quan

Supply the correct forms of the word in parentheses. 1. Phuong Linh arranged flowers the most .......................(attract) in the contest. 2. It is a contest in which ....................(participate) have to read two poems in English. 3. .......................(environment) are concerned about the use of dynamite to catch fish. 4. Years later, she passed me in the street without even a small sign of .......(recognize). 5. Nam put ................(press) on that towel to stop the bleeding. 6. After many years of ............(fail), Edison finally succeeded in inventing the light bulb. 7. We use first-aid in order to ease the victim’s pain and ......................(anxious). 8. She felt ....................(relief) after she passed the exam. 9. You’ll meet the tour guide on your ..................(arrive) at the hotel. 10. We can take buses or trains to Northern ......................(destine) of Nha Trang. 11. Sapa is considered the most beautiful .......(mountain) resort in the north of Viet Nam. 12. It’s now high time you knew how to dress and ....................(dress) yourself. 13. We are having a good time here. People on the island are very friendly and ...........(hospitality). 14. The police are interested in the sudden ............(appear) of the valuable painting. 15. I wrote .............(end) letters of application but I got no reply. 16. A fairy appeared and ...................................... ( MAGIC )changed her old clothes 17. The tiger wanted to see the farmer’s .................................. ( WISE ) 18. In that story, the prince got ........................( MARRY )to a poor girl 19. Let me get an .................................... ( APPLY ) form and I can fill out 20. He was ............................... ( FOOL ) to say that English is helpless

Rewrite sentences as directed so that it has the same meaning as the sentence given 1. Thinking of making toys from used paper was his interesting idea. It’s interesting that................................................................................................................... 2. He hasn’t come back to his home village for over 20 years now. It’s............................................................................................................................................ 3. That’s the strangest film I’ve ever seen. I have never.............................................................................................................................. 4. Please don’t interrupt me while I am speaking. I’d rather................................................................................................................................... 5. Get up now or you’ll be late for school. If............................................................................................................................................... 6. The last time we met each other was ten years ago. We haven’t............................................................................................................................... 7. Finding accommodation at busy time in Da Lat is difficult . It’s........................................................................................................................................... 8. Originally, tennis was an indoor game. Tennis used.............................................................................................................................. 9. My father prefers living in the countryside to living in the city. My father likes........................................................................................................................ 10. Nobody in my class is as intelligent as Lan. Lan is...................................................................................................................................... 11. Have you ever played a computer game before? Is this....................................................................................................................................... 12. France presented the Statue of Liberty to the United States in 1876. The Statue ............................................................................................................................... 13. The water was so cold that the children couldn’t swim in it. The water wasn’t..................................................................................................................... 14. He hasn’t chatted with his classmates through the Internet for ages. It’s ages..................................................................................................................................