First, think carefully and fill in carefully. (3 points for each small question, 30 points for * * *. )
1. The actual distance from Beijing to Tianjin is 120km. On a map, the distance between the two places is 3cm, and the scale of this map is ().
2. Rectangular playground, length120m, width 80m. Draw it on the map with the scale of 1 1000, with a length of () cm and a width of () cm.
3. Put two identical cylinders together to become a cylinder with a length of 30cm, but the surface area is reduced by 25. 12cm2, and the original volume of each cylinder is () cubic centimeters.
4. An insecticide, which is prepared from liquid medicine and water in the ratio of1:1500. If there are only 4 kilograms of liquid medicine now, you can make this pesticide into () kilograms.
5. The side area of the cylinder is 188.4 square decimeter, and the radius of the bottom surface is 2 decimeter. Its height is () decimeter.
6. There are two cylinders with equal base radii, and the height ratio is 3: 5. The volume of the second cylinder is 45 cubic centimeters, and the volume of the second cylinder is () cubic centimeters more than the first one.
7. Make 10 cylindrical ventilation pipes with iron sheet, each section is 80 cm long and the circumference of the bottom circle is 34 cm. At least iron () square meters is needed.
8. If the ratio of two ratios ab and cd is reciprocal, then the ratio of A, B, C and D can be ().
9. There is a wooden cube with a side length of 4 decimeters. Make this piece of wood into the largest cylinder, and the volume of this cylinder is ().
10, the bottom area of the cone is equal to the bottom area of the cylinder. It is known that the volume ratio of cone to cylinder is 16, the height of cylinder is 4.8, and the height of cone is () cm.
Third, choose carefully and sit in the right position. (2 points for each small question, *** 12 points. )
1, if A×2=B÷3, then a: b = ()
① 2:3 ② 3:2 ③ 1:6 ④6: 1
2. Measure the height and shadow length at the same time and place ()
① Out of proportion ② In direct proportion ③ In inverse proportion.
3. If the distance of 3 cm on the map indicates that the actual distance is 1.5 mm, then the scale of this map is ().
① 1:20 ② 1:2 ③20: 1
4. On the graph with the scale of 1: 8, the diameter ratio of the two circles A and B is 2: 3, so the actual diameter ratio of the two circles A and B is ().
① 1 :8 ②4 :9 ③2 :3
5, a cylinder, the side to get a square, its height is () times the radius of the bottom.
①2 ② 4 ③π ④2π
6. Cylinders and cones are equal in height and volume. The bottom area of a cone is 12 square decimeter, and the bottom area of a cylinder is ().
①4 square decimeter ② 12 square decimeter ③36 square decimeter
Third, carefully scrutinize and be a good referee. (2 points for each small question, 20 points for * * *. )
1. In proportion, the quotient of the product of two internal terms and two external terms is equal to 1. ( )
The radius of a circle is proportional to its area. ( )
3. The processing time is fixed, and the number of parts to be processed is inversely proportional to the time required to process each part. ( )
4. The actual distance is certain, and the distance on the map is proportional to the scale. ( )
5. In the case of a certain area, the side length of the square brick is inversely proportional to the number of blocks required. ( )
6. Draw a rectangular playground on the map with the scale of 1: 1000. The playground area on the map is smaller than the actual one 1000 times. ( )
7. If the side areas of two cylinders are equal, the perimeters of the bottoms of the two cylinders must be equal. ( )
8. The bottoms and heights of cylinders and cones are equal, and their volumes differ by 48 cubic decimeters. The volume of this cone should be 24 cubic decimeters. ( )
9. The height of the cone is unchanged, the radius of the bottom surface is expanded by 2 times, and the volume is also expanded by 2 times. ( )
10. On the map with the scale of 1: 100, the area of a square is 9 square centimeters, and the actual area of this square is 9÷ 1 100 =900 square centimeters. ( )
Fourth, carefully examine the questions and calculate them carefully. (*** 14)
1, write directly. (65438+ 0 point for each small question)
7 ÷ 1.4= 0.9+99 ×0.9 = 400÷ 25÷ 8=
1.25× 0.8 = (2.4+ 1.2)÷ 6= 1.9× 4 ×0.5=
2. Solution ratio. (2 points for each small question)
8: 13=24:х 16 :χ =29 :8 15 4024 =5χ χ25 = 1.27.5
Fifth, solve the problems in life. (1 4 points for the question and 5 points for other questions) 1. The liquid medicine and water in pesticides are prepared according to the ratio of 1: 1500. Now there are 5 grams of this potion. How many grams of pesticide can you mix? (4 points)
2. A conical sand pile with a bottom area of15m2 and a height of 2m. How thick can this pile of sand be spread on a road 400 meters long and 3 meters wide?
3. The diameter of the bottom of the cylindrical glass container is10cm. After Xiao Ming took an iron block out of the water in this container, the water level dropped by 3 cm. What is the volume of this iron block?
4. A cylindrical iron drum without a cover, with a height of 8 decimeters and a bottom diameter of 34. Grandpa Wang wants to make two buckets like this. How many square decimetres of iron will be used? Take the approximate value in one way and keep the whole ten square decimeters. )
5. After a cylindrical steel with a length of 1.5m is cut into three sections, the surface area is increased by 9.6 square decimeters. What is the original volume of this steel?