Decimal Math Problem 5th Grade

1.Dig a ditch and measure it to be 10 centimetres long on a map on a scale of 1,300. What is the actual distance of this aqueduct in meters?

s = 10 * 300 = 3000 cm = 30 meters.

2.On a traffic map, 4 centimeters are used to represent the two villages of A and B that are 8 kilometers apart, and the scale of this map is obtained.

8000 meters = 800000 cm So scale = 4: 800000 = 1: 200000

3.The distance between the two cities is measured on a map to be 8 centimeters, and the ratio of this soil is known to be 1:12000000, and the actual distance between the two cities is obtained.

s = 8 * 12000000 = 96000000 cm = 960000 meters = 960 km.

4.The foundation of a school building is 75 meters long and 32 meters wide. Drawing on a scale of 1:1200 in the design, how many centimeters should be drawn in length and width? (Solved in two ways: equations and arithmetic).

Equation method: Let the length be x centimeters and the width be y centimeters.

x * 1200 = 75 * 100 x = centimeters.

y*1200=32*100 y=8 3 cm.

Arithmetic: length = 75 * 100 1200 = cm.

Width = 32 * 100 1200 = 8 3 cm.

Centimeter = 30 meters.

m = 800,000 cm.

Centimeter = 960 km.

m = 7500 cm.

32 meters = 3200 centimeters.

Dissolution: x cm long on the figure.

x/（1/1200）=7500

x=25/4

Set: x cm wide on the figure.

x/（1/1200）=3200

x=8/3

km = 8000 m = 800000cm

Equation method. Let the length be x and the width be y, and the equation is obtained according to the meaning of the problem, x: 75 = 1:1200 y: 32 = 1:1200

b arithmetic. It's the process of solving the above equation.

1 300 = 3000 cm = 30 meters.

1 12000000 = 96000000 cm = 960 km.

4. Solution: The length should be drawn x cm. The width should be drawn y cm.

75 m = 7500 cm 32 m = 3200 cm.

x/7500=1/1200 y/3200=1/12001200x=7500 1200y=3200x= y≈

Originally, the teacher asked Xiao Ming to buy x exercise books.

x = 17 copies.

Need a process? Assume in the simplest way, and the answer comes out. Suppose the small cubes are lined up. The length of the edges on both sides is 16, 72-16 = 56, the length of the long edges is four, 56 4 = 14, 14 2 = 7, the answer is 7.

10 points for a correct one, 150 points for copying and assuming that 15 questions are done correctly, and the actual score is 88 points, so the difference is 62 points, therefore, 62 points is the loss of points for the wrong question and the question that is not done, 4 points will be deducted for the wrong question, and the actual wrong question will be 14 points less, and if you don't do 0 points, you will get 10 points less, then 62 points just include 3 14 points and 2 10 points. So she answered 10 questions correctly, got 3 questions wrong, and didn't do 2 questions.

If you buy 10 towels, it will cost 64 yuan, and now you have spent a total of 118 yuan, which means that the towels you bought are more than 10, so the number of towels you buy is, (118-10 towels.

(118-10×

So Aunt Liu bought back 12 + 10 = 22 towels.

(32 * Drainage Fee + 32 * Water Charge) 2= (Yuan) Brother Instant's miscalculation There is no such number as 34 at all.

jianjdiaodiu he didn't know how to say it and was absolutely wrong anyway.

The total cost of two months = 34 * yuan), the average cost of each month = yuan).

Water charge) + (drainage fee) = yuan in the division by 2 ah people are sharing 32 cubic meters.