Page 6 answers 1, (1) × (2) √ (3) √ (4 )× 2,70,95,55,65. 3, 306 ÷ 360 = 85% ...8.5 fold 4,2800-2800× 85% = 420 (yuan) children's bookstores are cheaper. The answer on page 7 is 1, 360×80%=288 (yuan) 440×75%=330 (yuan) 2 100×88%= 1848 (yuan) 2. (1)5×65%=3.25 (yuan) 3.8×65%=2.47 (yuan) 6×65%=3.9 (yuan) (2) 10÷3.25≈3 (package) 65433. 3. 5800×80%×90%=4 176 (yuan) Page 8 Answer 1, 1500×80%= 1200 (yuan) 900×80%=720. The answers on page 9 are 1, (1)85%x, 1.85x(2)75%x, 0.25x2,30,203, x+70% x = 510x = 3000. 24 ÷ (1-20%) = 30 (only) 30×20%=6 (only) answer: 30 white 5, 126÷( 1+80%)=70 (kWh). 2. (1)/monthly coal tonnage-February ratio1monthly tonnage saved = February coal tonnage x-20% x = 1.6x = 2 (2) car speed+train speed faster than car speed = train speed x+35.
X+20% x = 30x = 25 (2) 30+30× 20% = 36 (kg) page 1 1 answer 1, solution: suppose that X million TV sets were produced in the second half of last year. X- 1/5x = 48x = 602。 Solution: let Xiaoli save X yuan. X+110x = 88x = 803. Solution: Let light travel at the speed of x million kilometers per second. 1/5x-2 = 4x = 304。 Solution: Suppose there are X girls and 4 /5X boys. X+4/5X=540X=3004/5=240 Page 12 Answer 1, (1)60×4/5=48 (tree) (2) Solution: There are x pear trees. 5/4x = 60x = 48 (3) 60-60x1/5 = 48 (tree) (4) Solution: there are x pear trees. X+ 1/4X=60X=482。 Solution: Suppose there are X cocks and 3/8X hens. X—3/8X=40X=643/8X=243。 Solution: Suppose there are X male employees and 2/5X female employees. X+2/5X=840X=600 Page 13 Answer 1, (1)62.5,160,37.5,60. (2)240,48,80。 2、( 1)44÷(32+ 12+44)=50%(2)(44— 12)÷ 12≈26.67%3、(4800—2500)÷2500=92%4、(240— 180)÷240=25%
180 ÷ 240 = 0.75 ... 75% off page 14 answer 1, (1)150-150× 40% = 90 (. 800×3.06%2=48.96 (yuan) 48.96-48.96 ≈ 46.5/(yuan) 800+46.5 1=846.5 1 (yuan) 3,/kloc-0. x-85% x = 4.5 15% x = 4.5x = 30(2)25.5÷85% = 30(km)30×( 1-85%)= 4.5(km)3。 Solution: This product is designed for. X-1 5% x = 34085% x = 340x = 4004, (1) is 20% more than volleyball x+x× 20% = 60 (2) is 20% less than volleyball x-x× 20% = 60 (3 Seen from the front, it is rectangular; Seen from the side, it is a rectangular cone; Seen from above, it is a circle; Seen from the front, it is triangular; Triangle 4 Seen from the side, the first figure is a cone after one revolution; The second figure is the cylinder after one revolution; After the third figure rotates once, it is the answer of the second figure on page 17.
1, (1) Rectangular perimeter height (2)53 1.42, ① 3.14× 5× 8 =125.6 cm2 ② 3.14× (40× 2 )× 20 =15cm = 0.15m3./kloc-0. 78.3438+0438+02， Bottom area: 3.14× (2.5÷ 2) 2× 2 = 9.8125m2 Side area: 3.14× 2.5× 4 = 31.4m2 Surface area: 9.8/. ×8 = 1 13.04 square decimeter 4, 62.8 ÷ 3.14 = 20m20 ÷ 2 =10 decimeter 3.14×10. . The surface area of lateral area is 187.92 cm2 94.2 cm2 2565.2 cm2 7910.28 cm2 3452. 16 m2 854.08 m2 2, 3.14× 0.2×1××××××××××××××××××××××××××××××××××××××××××××××××××××××××××
The answer on page 20 is 1, (1) high bottom area (2) V = SH (3) 2. 1.
2, 3. 14× (0.2 ÷ 2) 2× 3 = 0.0942 m3, 40 ÷ 2 = 20cm3.14× 202× 60 = 75,360 cm3 = 75.36 liters, 75. 3.14×10×10 = 314 square centimeter 5024 ÷ 3 14 = 16 cm 5, 5× 8× 7.8 = 3. ①8÷2 = 4cm 3. 14×42×6 = 30 1.44 cm3 23. 14×52×9 = 706.5 mm3 2，6 ÷ 2 = 3cm 3. 14× 32× 6538。 3.14× 22× 2.5 = 31.4m331.4x550 =1727kg =1.727t 4,8 ÷ 2 = 4m3. ① Surface area: 345.4cm2 Volume: 47 1 cm3 ② Surface area: 401.92mm2 Volume: 602.88cm2,16 ÷ 2 = 8cm = 0.08m3.14× m3. 4x52x6 ① 3.14× 62× 3 = 339.12 cubic centimeter ② 3.14× (5 ÷ 2) ②×10 =196.25 cubic decimeter.
4, 3 1 4 ÷ (3.14×10× 2) = 5cm 3.14×102× 5 =1570 cubic centimeters. 3 = 75.36 cubic centimeters 23.14× (8 ÷ 2) 2×15×1/3 = 251.2 cubic centimeters ③, 25.12 ÷. kloc-0/4×(4÷2)2× 1.5×= 6.28 m3，6÷2 = 3cm 3. 14×32×20 = 565.2cm 3. 14×32×4。 3.14× 22× 3×1/3 ÷ 2/7 = 43.96 cubic decimeter 5,3.14× 62× 8× (1~1/3)
3. 14×2.52×2 = 39.25 cm2 15.7× 15.7 = 246.49 cm2 39.25 ~ 246.49 = 285.74 cm2 5， 10 ÷ 2 =
The answer on page 26 is 1, (1)3 times (2)150.75438+041.32 shape bottom radius bottom diameter bottom perimeter high surface area volume cylinder10cm 20cm62.8cm/kloc-.
2/5X=240 Page 27 Answer 1, (1)×(2)×(3)√2, (1) 3.14× (12 ÷ 2) 2×12 =1356.48 cubic centimeters (2)12×/kloc-. 3 = 40 1.92 cubic centimeter 4, (1) 25.12 ÷ 3.14 ÷ 2 = 4. 3× 1.35 = 40.6944 tons ≈4 1 ton Page 28 Answer 1, (1)C(2)A(3)C2, (1) 3.14× 40× 20 = 2512cm2 (2) 3.14× (40 ÷ 2) 2× 20 (4-1) The product of (1) variation is inversely proportional to (2) xy = k (k.3), because the product is certain. 4.( 1) ○ (2) δ (3) Out of proportion (4) δ (5) δ Page 30 Answer 1. (1) 43 (2) parallelogram (3) 632.25. 12 cm2 650. 94/9 (2) 9/88/9192. (1) 25 (2) The black rabbit is 3.80g of the white rabbit. The answer on page 32 is 1. (1) nitrogen 78 carbon dioxide and other impurities 0.06 (2) 0.266.
The answer on page 33 is 1. (1) 737 (2) 642.53. (1) 4648 (2) 4236 (3) Male classmate 4. The average number of people is 45. The answer on page 34 is 1. (65438 1) Mode 40 Average 40.4 Median 40(2) Median 3. (1) The median is 4000 and the average is 5980. (2) The median is more appropriate. (3) Because 12500 is too large. The answer on page 35 is 1. (1) 40℃-10℃ (2) 3.051.2 (3) (4) 85% 2. (1) 322,000 (2) 6.304 million. 24,000 4.( 1) Percentile (2) Ten digits (2) Four digits (3) Two million instead of 0.020.002 (4) 0.850.8505. (1) × (2 )× (3 )× the answer on page 36. 6、2 1; 5、2 1、3 1、5 1、; 2、6; (3)26(4)3362.( 1)√(2)√(3)×(4)×3.380308830703370877307083078038707804.( 1)8.0258.0528.2058.5028.250(2)80.2580.5220.8520.5850.8250.28(3) 20.585. > < = > = > 6. (1) 0.640.2560.1024 (2) 0.50.40.3 Page 37 Answer1.10000. 80.0082.( 1)A(2)C(3)B(4)B 3. 14648 14.284。 ( 1)438 18.650 1402 196.8 13 16896.8(2) 1.7080.4880.3895.6004200
The answer on page 38 is 1.2/3 hectares, 3/2 hours, and 2.432 people are enough for 3.62.5%.
4.77.4 yuan 206 1.925. (1) 357 yuan (2)340 yuan's answer on page 39 is 1. ( 1)+4.39 (2)+4.8 (3) × 7.5 (4) × 4.4 1003.( 1)2857 1442857 14287 14285857 142(2) 100 1 101111101065438 (1) 3 Positive and negative ratio 1. (3) It is in direct proportion, because the ratio of the amount of money subscribed to the score is always equal to 26, which is a fixed value. 2.1.4,9.16.25, which is out of proportion. 3.( 1) also changes, and the ratio is always (2)4. (1)√(2)√(3)× Page 42 Answer: 1. (1) is proportional, because the ratio of road construction length to road construction time is always equal to 2.5, which is a fixed value. (2) 8.75km,12.5km2. (1) 200,300,400,500 (2) is slightly proportional to (3), because the ratio of travel distance to time is always equal to 100, which is a constant value. (4) 250,3.6 Answer 1 Page 43. (1) 3500: 5 = 700, 4900: 7 = 700, and the ratio indicates the speed of the aircraft. (2) is in direct proportion, because their ratio must be (3) slightly (4)3 hours 4.3 hours 2. (1)√(2)√(3)×(4)× answer on page 44 1. (1) has also changed. Product (2)xy=k (sure) 2. The product of (1) 4× 30 =12010×/2 =12020× 6 =120 is equal to (2).
3. Because the length of 24×1= 2416×1.5 = 2412× 2 = 24 ... The length of a rectangle is inversely proportional to the width, and the length× width is equal to 24 (certain). 4.( 1) Circle (2) Triangle (3) is out of proportion. (4) Triangle (5) Triangle Page 45 Answer 1. (1) Because 20× 50 =10040× 25 =100×10 =1000 ... The number of days of burning coal varies with the change of the tons of coal burned every day, and the number of days of burning coal× the tons of coal burned every day. So the two quantities in the table are inversely proportional (2) Because 20× 3 = 6015× 4 = 606×10 = 60 ... The base of the parallelogram changes with the height of the parallelogram, and the base× height = 60 (certain), so the two quantities in the table are inversely proportional. This table is slightly proportional. 3.( 1) is proportional. (2) It is inversely proportional. (3) Out of proportion. (4) It is inversely proportional. (5) Out of proportion. (6) It is inversely proportional. The answer on page 46. Problem solving strategies 1. (1) 43.62.8(dm)4.25 The answer on page 47 is 1. ( 1) 4/55/94/9 (2) 9/88/9 1/92.( 1) 7/5x = 35x = 25(。 2 1/325/492.( 1)5/95/4(2)4/33/43.5/64. 1/2+ 1/4+ 1/8+ 1/ 16+ 1/32=3 1/32
Answer 7 on page 49. Statistics 1. (1) nitrogen 78 carbon dioxide and other impurities 0.06(2)0.2 1(3) omit 2. (1)30 copies, 24 copies and 54 copies 12 copies (2) 265438.
2.53.( 1)4648(2)42364. Mode 45 has an average of 45 pages 5 1 answer 1. (1)158 (2)161(.2 (1)). The mode is 40, the median is 40, and the average is 40.4(2). 3.( 1) The median is 3800 and the average is 5 180(2) Because there are two large numbers in the data, it is more appropriate to use the median (3) because it is 12500. Page 52 Answer Unit 8 1. ( 1) 40℃; -10℃ (2) 3.051.26.05 (3) 0.49 (4) 85% 2. (1) 322,000 (2) 6.3 million four hundred (3)1494. (2)1/94 (3) 200.020.002 (4) 0.850.8505. (1) × (2 )× (3 )× answer on page 53 1. (65438 132639(2)253 1; 62 15 1; 52 13 15 1; 26(3)24(4)3362.( 1)√(2)√(3)×(4)×3.3873787387838738373803088038303073707037308708077087804.( 1)8.0258.2508.0528.2058.5028.520(2) 80.2580.5220.8 520.5850.2850.82 (3) 20.585. > < = > 6. (1) 0.642.5610.24 (2)/kloc-0.
Answer 1 on page 55. (1) 96 (2)1/65/6 (3)17/52.2/53/79/56/73.492 ÷ 500 = 98.4% 4.500 ÷ 500. (/kloc-0 1)5068.60666666666 The answer on page 57 is 1. 1/2÷3/4=2/3 (hectare) 3/4 ÷1/2 = 3/.
(2) The number of kilograms of pears ×2/3= the number of kilograms of apples. Solution: suppose there are x kilograms of pears. 2/3x =100x =1504.60 ÷ 80 = 3/4 (80-60) ÷ 60 =1/3 The answer on page 59 is1.40× 3 \. kloc-0/)+4.39(2)+4.8(3)×7.5(4)×4(5)×b+c 2.456- 198 = 456-200+2 = 25845×0.99 = 45× 1-45×0.0 1 = 44.552.5×36 = 2.5×4×9 = 90720( / kloc-0/)2857 1442857 157 14287 14285857 142(2) 100 165438+ 000 1 1 100 1 1 100 1 1 1 1 1 1 100. 152.9696.2590933.( 1)( 163- 160)÷ / Kloc-0/60 =1.875% (2) (45-40) ÷ 40 =12.5% The answer on page 62 is1.16km2.2/kloc-0.
3 (1) 35% (2)1560 (3) 2400 Page 63 Answer1. (1) √ (2) × (3) √ (4) × (5) √ 2. (65438) (3) a+2b (4) 3mm3.x = 5x = 45x = 2x =14.3/2 Page 64. 8 48058000 Page 65 Answer1x = 0.4x = 2x =1.72183600045438+001680 (2) 20: 320/3 (3)/.
The answer on page 67 is 1( 1) not proportional (2) proportional (3) inversely proportional 2( 1) proportional (2) inversely proportional (3) not proportional 3( 1) proportional (2) on page 86.
Page 765438 +0 Answer1(1) × (2) √ (3) √ (4) × 2 (1) 25.1250.24 (2) 24 (3) 0.09 (Figure omitted) (2) The shortest circumference of a rectangle is 56 cm. 3.(80+60) × 30 ÷ 2 = 2 100 m2 3150 ÷ 2100 =1.5 kg 4,8 ÷ 2 = 4 decimeters 3./.
8× 4 ÷ 2× 2 = 32 square decimeter 50.24-32 = 18.24 square decimeter 5, 24× 1.2 = 28.8 square meter 0.6× 0.6 ÷ 2 = 0. 18 square meter 28 Triangle: perimeter 1.5× 3 = 4.5cm area1.5×1.3 ÷ 2 = 0.975cm trapezoid: perimeter 2.5 ﹢1﹢ 2.5+2 = (omitted) 3, 5× 10 = 50 cm2 × 5 = 3 cm (12+ 10 )× Then the length of the red line is: πd1-π d2+π d3 = π (d/kloc-) The answer on page 74 is 1, (1)6 relative to 12 relative to (2)66 12 12(3) the same circle as a rectangle (4) the circumference of the bottom of a circle (2) (rectangular The squares 1 and 3 are left and right sides, and the squares 4 and 5 are front and back sides 2,2 √ 3 √ 4, (omitted) 4, because 7× 8 = 56 square centimeters 7× 7 = 49 square centimeters 56 > 49.
Therefore, this cuboid will not leak from a square hole with a side length of 7 cm. The answer on page 76 is 1, √×√2, 94.2 ÷ 3. 14 = 30× 30× 6 = 5400 cm2, and S table = π DH ﹢ π R2 = 3.14× 4. 2 = 62.8- 12.56 = 75.36 square decimeter 75.36× 2 = 150.72 square decimeter 4, and s side = π DH = 3.14×1.. 2.4 ÷ 1 2 = 0.2× 0.2× 6 = 0.24m2 Page 77 Answer1,5.6 liters 0.08 cubic meters 1500 cubic centimeters 3050 cubic decimeters 2. Can form a cone V-Cone =/kloc-.
1, ① cuboid: surface area (15×10 ﹢15× 8 ﹢10× 8). × 2 = 700 cm2 volume15×10× 8 =1200 cm3 ② cube: surface area 10× 10× 6 = 600 cm2 volume10×/kloc. .14× 8×12 ~ 2× 3.14× 4 = 301.44 ~100.48 = 40/kloc-0. 4× 22× 3 = 37.68 cubic centimeters 8× 5× 2 = 80 cubic centimeters 80+37.68 = 1 17.68 cubic centimeters = 168. 3. (1) ① 5 ÷ 2 = 2.5m S table = S-side bottom = π DH π R2 = 3. 1 4× 0.8× 3.14× 2.5× 2.5 = 3. 5.7× 1 = 15.7 tons Page 79 Answer surface area: 1× 2 = 2 decimeter 3.6544
39.4384-6.28 = 45.7 184 square decimeter volume: 3.14×12× 6.28 =19.7192 cubic decimeter 2,/kloc-0. .2 = 5.024 m2 532÷2 = 16 cm3 . 14x 16x 16x 40 = 32 153.6 cm3 . 32 x3/4 = 24c m2 4÷2 = 12cm 3. 1 4× 1 2× 1 2× 40 = 1 8086 The answer on page 80 is 1, 13④ is axisymmetric drawing (omitted) 2, (omitted) 3, (1). (1) 3.14× (6 ÷ 2) 2 ÷ 4 = 7.065 square decimeter (2) 20× 10 ÷ 2 = 100 square centimeter 3, (omitted)
1, slightly 2, (1) slightly (2) (3,5) (3) 23, (1) slightly (2) west, 8. (3) Omit (4) 4)( 10/0,3) 83rd. Southeast 502402, (1) east 200 north 150 northeast 45300. (2) 80450 northwest, 4050 northeast and 50400 northwest. (3) omission
The answer on page 84 is 1, (1)×(2)×2, omitting 3, (1) sweeping dust (2)40(3)6(4) omitting the answer on page 85, (1) 99. 125(2) Omit (3)1; 3(4) omitted 2. The mode of (1) is 20, the median is 185 and the average is 16. (2) The median is more appropriate. The answer on page 86 is 1, slightly 2, (1) slightly (2) 960×18.8% =180.48 (ten thousand square kilometers) 960×26%=249.6 (ten thousand square kilometers).
960×9.9%=95.04 (ten thousand square kilometers) 960× 1 2% = 1 5.2 (ten thousand square kilometers) The answer on page 87 is1,(1) Maybe (2. (1) Three black balls and three white balls are equally likely to contact the black ball (2) Four black balls and two white balls are more likely to contact the black ball (3) Six white balls can't contact the white ball (4) Two black balls and four white balls are more likely to contact the white ball (3, slightly 4, (1) ①√②. The probability of winning is 1/2. The answer on page 88 is 1, (1) omitting (2)2, (1)1/2,3/10,1/5 (2) 7//.
5,96,96% 7, 1.6 or 1 or 2.258,384,5 1 2, 1, C2, A3, C4, C5, C6, b3,1. 20X=8.5 solution:1/8x =1/40x =10x =1/53,3/8×11+5/8× 655. ×10/1= 9/20 ÷ [1/2× 6/5] =/kloc-0 /×10/1. 3.3. 14(6÷2)2× 12[ Note: 2 is a square, that is, the square of (6÷2) ]=3. 14×32× 12[ Note
A: Such a can can hold 339. 12 ml of beverage. 4, 4+5=9270×4/9= 120 (Ben) 270×5/9= 150 (Ben) A: The library bought 150 story books and 120 science and technology books. V. 1, omitted 2. (1) B 4 (2) The profit created by a workshop is relatively low, so it should be saved in the future. Sixth, ellipsis
Hope to adopt. Thank you.