Elementary school math problems need to be a process or an idea

I'll admit I've written a little too much ... Take your time.

The distance traveled by the bus: 40 5 8 = 25 (km).

Speed ratio = distance ratio).

If the bus does not go first, it will go 7 (7+8)=7 15

Since the first walk is 5 8 hours, 60% has walked 25 kilometers more than 7 15. 】

25 2 15 = km).

A: ...2. Two situations.

1) The car has not passed the midpoint.

34+250) (7-4) 7 6=110 and 4 9 (km).

Distance Speed difference Car speed 6 hours.

2) The car has passed the halfway point.

250-34) (7-4) 7 6= 87 and 8 9 (km).

A: ...3. You can list equations (I really can't think of an arithmetic solution, sorry).

Solution: Let A have x kg in basket and B (x-10-10) kg.

According to A - 10 kg = B + 10 kg)

x-10)×(1+1/3)+5=(x-10-10)-10

1 3 more than A, 5 kg more = B].

x = 145A: 145 kg.

B: 145-10-10=125 (kg) Answer: .

The whole process is regarded as unit one).

Express speed: 1 12 = 1 12

Slow speed: 1 16 = 1 16

Unit 1 minus the distance traveled by the slow train when the fast train stops for 2 hours is equal to the length of the distance traveled by the fast train and the slow train at the same time).

7 8) (1 12 + 1 16) = 6 (hours).

The distance divided by the speed is equal to the time, and 6 hours does not include 2 hours).

360 6 = 60 (km).

The distance traveled by the express train divided by 6 hours is equal to the speed at which the express train travels per hour. ）

Fast speed: Slow speed = 1 12:1 16 = 4:3

Slow speed: 60 4 3 = 45 (km).

A: ...5. Solve the equation, I can't think of a formula to solve it... I'm sorry.

Solution: Set up x master tasks and apprentices (880-x).

1/8x+1/10(880-x)=102

No need to explain)

x=560 Master has produced: 560 (1-1 8)=490 (pcs).

Apprentice. 880-490=390 (pcs).

A: ...6. Isn't it the same as the previous 4 questions?

7. Use the backward method.

Before the next day's maintenance.

20+2) (1-1 3)=33 (sets).

The remaining 20 units on the second day plus those 2 units are 1-1 3 on the second day, and then find out what is left on the first day. ）

33-5) (1 2) = 56 (sets).

Similar to the above, the final result is the total amount of this batch of machines).

A few less (amounts) than what (the fraction of one unit) is to add this number to equal that, and a few more is the opposite] Answer: .

I still miss this kind of problem

The ergonomics of A is 27 40-1 8 * 5 = 1 20

This project is done by A alone, and it takes 1 1 20 = 20 days.

A: He got a total of 6 questions right.

Ideas: 6 points for a correct answer, and 4 points for a wrong answer, that is, for every five questions, 2 correct answers and 3 wrong answers are 0 points. Of the 15 questions, 6 were answered correctly, and 9 were answered incorrectly.

Thirty-six points are awarded for answering six questions correctly (6x6=36), and thirty-six points are deducted for answering nine questions incorrectly (4x9=36), because two correct answers are twelve points, and three wrong answers are also twelve points, so two of the five questions are correct and three are wrong, and fifteen questions are six correct and nine wrong.

These two numbers are 28 and 280

Let one be a and the other be b

Removing the last zero is equivalent to shrinking by a factor of ten.

a+b=308 and a10=b

A=280, B=28

The volume of water raised is the volume of the cone.

The volume of water elevation is pi*20 2*1 (radius is 20), and the volume of the cone is 1 3*pi*10 2*h

So h=12, i.e. the iron block is 12 centimeters high.

After all immersion in the water, the water surface of the tank is 1 cm higher than the original, so the volume of the cone is equal to the volume of the rising water surface, i.e.: v *r 2*h= *(40 2) 2*1=400 cubic centimeters because the volume of the cone is 1 3*sh

So 1 3* *10 2*h=400

H = 12 cm.

A: The height of this piece of iron is 12 centimeters.

The height is 12 cm. The volume of change is essentially the volume of the cone. The volume of the cylinder of change = s*h= squared *1+= the volume of the cone = thirds are one s*h = one-third * squared *h=one-third * the two equations are equal, so one-third * h=12 (sorry, no math notation found).

The diameter is 40 cm, and the radius = 20 cm.

Iron block volume = cubic centimeters.

Iron volume = 1 3 height = 1256 cubic centimeters.

Height = 1256 3 314 = 12 cm.

Solution: Let's take x kilograms of oranges from box B and put them in box A.

Then: 2(120-x)=180+x

240-2x=180+x

x=20A:. . .

Idea: Take some oranges from box B and put them in box A. For trousers, there are as many oranges in box B as there are more oranges in box A. It can be seen from the simple problem of the wheel reed that the oranges in box A are twice as large as those in box B, so the equation can be listed: 2(120-x)=180+x

Solution: Let's take x kilograms of oranges from box B and put them in box A.

Then: 2(120-x)=180+x

240-2x=180+x

x=20 Answer: How many kilograms of oranges did Wheel Lu Jian take in box B and put them in box A.

Idea: Take some oranges from box B and put them in box A. Then there are as many oranges in box B as there are more oranges in box A. As can be seen from the problem, the oranges in box A are twice as large as those in box B, so the equation can be listed as follows: 2(120-x)=180+x