1, a book has 900 pages. Xiao Ming read 308 pages in the first week and 28 1 page in the second week. How many pages does Xiaoming have left?

2. Parents' meeting was held in the second and third grades, and 800 chairs were prepared. There are 276 second-grade parents and 356 third-grade parents. Excuse me, are there enough chairs prepared by the school?

The school organizes students to visit the museum. There were 580 visitors in the morning, less in the afternoon than in the morning 187. How many students visited the museum on this day?

Unit 3: Quadrilateral

I. Fill in the blanks:

1, () and () have quadrilateral surfaces. (Please name two objects)

2. Enclose a square with a 20-decimeter-long iron wire, and the side length of this square is () decimeter.

3. Use 9 small squares to make a big square with a side length of 1 cm. The circumference of this big square is () cm.

Second, solve the problem:

1, Xiao Ming ran 1 circle along a rectangular playground 45 meters long and 35 meters wide. How many meters is a * * *?

2. A square table with a side length of 10 decimeter. Put a lace around the desktop. How many decimetres is this belt? How many meters?

Grandma will fence the vegetable fields. If there is a wall (as shown in the picture), how many meters does the fence need at least?

The circumference of a rectangle is 20cm, so what is its length and width? How many possibilities are there (draw it)

Is the 5.3-meter-long aluminum bar enough for my desktop? If not, how many minutes?

6. A lace is 28 decimeters long, just around a square table. What is the side length of this table?

7. The central square is 350 meters long and 200 meters wide. Xiaoming rides his bike around the square. How many meters did Xiaoming ride once?

8. Obviously, cut a square from a rectangular piece of paper 26 cm long and 20 cm wide. What is the circumference of this square?

9. A wire can surround a square with a side length of 10 decimeter, and now it becomes a rectangle. If the width of this rectangle is 7 decimeters, how long is it?

Third, true or false:

1, a quadrilateral with four equal sides must be a square. ()

When the side length of a square is doubled, the perimeter of the square is also doubled. ()

3. Square is a special rectangle.