A question in the fifth grade mathematics summer vacation homework of Chongshu Bureau, ask the maste

Divisible by 5, mantissa 0,5

Divisible by 2, the mantissa is even.

So the mantissa 0 is divisible by 3, all bits add up to be divisible by 3, 4x70, and you add up to 11+x, so x=1, 12 is ok or equal to 4 or 7

The title is a bit vague.

Is it a four-digit number that is divisible at the same time?

If yes.

There are three scenarios.

Divisible by 5, the mantissa is set at 0 or 5. If it is 5, then it is not divisible by 2, so the mantissa is 0

divisible by 3, then the addition of these four numbers as long as they are divisible by 3 can be used, according to this inference, the second number can be 1, 4, 7

The common multiple of 2 and 5 is 0, so 4()70 is determined, and the multiple of 3 is: the numbers in each digit add up to a multiple of 3. So 4+1+7+0=12 4+4+7+0=15 4+7+7+0=18

The 0,5 ending is divisible by 5.

The 02468 ending is divisible by 2.

An integer whose sum is three is divisible by three. In summary.

If it is divisible by 235, the mantissa can only be 0, and the first three digits must be divisible by 3, so there are only 4170 4470 4770

The height of the water is 45 cm = meters, so a total of cubic meters = liters.

There are too many twists and turns in this question, and the analysis is as follows:

According to the inscription, cutting into two cuboids adds 2 bottom surfaces, increasing 240 190 50 square centimeters.

Then a base area is: 50 2 25 The square root of the bottom side is 25 cm long.

Surface area 190 Two bottom 50 side area 140

The sides are 4 sides, one side is 140 4 35 and the side height is 35 5 7 cm.

The volume of the original box: the base area is high.

25 7 175 cubic centimeters.

The resulting cube has 12 equal sides.

The length of the side is 36 12 = 3

The area of a polygon is 3*3=9

6 sides are 9*6=54 square centimeters.

Combined, several of them can only eat a third of you.

1/8 + 1/16 + 1/48 + 1/24 = 1/4.

Xiao Ming three-quarters.

A quarter divided by a third = one-third.

Xiaoli, Huanhuan, Xiaoying and Nini can only eat one piece.

Xiaoying can only eat one-twelfth of you.

(32-4 2) 4 = 8 cm.

8+4 2=16 cm The width of the original.

16 32 = 512 square centimeters.

A: The area is 512 square centimeters.

10 10 (25 20) = 2 cm 15-2 = 13 cm.

A: The depth of the water is 13 centimeters.

2 = 4 square decimeters = 2 2

The original edge length is 2 decimeters.

Surface area: 2 2 6 = 24 square decimeters.

Volume: 2 2 2 = 8 cubic decimeters.

1. You can make a model out of a piece of paper for a clear guide The height of the container is 4cm, and the bottom edge of one of them is 32-4-4=24

According to the volume formula, the other bottom side is 768 24 4=8, then the length of the other side of the rectangle comes out: 8+4+4=16

So the area is: 32 x 16 = 512

2,15-10x10x10 (25x10)=133, two more faces are added, so each face is 4, the side length of the cube is 2, and the surface area and volume can be found.

1.The height of the title is 4 cm, the length should be 32-4x2 = 24 cm, and the volume is 768, at this time 768 4 24 = 8 cm is wide, then the original width is 8 + 2x4 = 16 cm, so the area is 16x32 = 512 square centimeters.

2. The water depth is 15, and the iron block is 10 high, then it is completely entered into the water, and the volume is 25x20x15-10x10x10 = 6500, and it is 6500 25 20 = 13 cm after being taken out.

3. A square of larvae increases by 4 square decimeters, then the side length is 2 decimeters, the original surface area is 2x2x6 = 24 square decimeters, and the volume is 2x2x2 = 8 cubic decimeters.

Question 1: Set the width x cm

32-4*2）*4*(x-2*4)=768x=16

32*16=512cm

Question 2: The total volume is 25*20*15=7500 and the volume of iron is 10*10*10=1000

6500/25*20=13cm

Question 3: 8 2=4

The edge length is 2, and the surface area is 2*2*6=24

If there is anything you don't understand, you can ask again! I wish you good luck learning to keep up with the castle tower.

, 768 (32-4 2) 4 = 8 cm.

8+4 2=16 cm The width of the original.

16 32 = 512 square centimeters.

A: The area is 512 square centimeters.

The total volume of 2 water and iron is 25 20 15 = 7500cm cubic ) - (iron 10 10 10 = 1000cm cubic meter) = 6500cm cubic meter, 6500 25 20 = 13cm, and the water depth in the water tank is 13cm

2 = 4 square decimeters = 2 2

The original edge length is 2 decimeters.

Surface area: 2 2 6 = 24 square decimeters.

Volume: 2 2 2 = 8 cubic decimeters.

What you need to pay attention to:

Question 1: Cut off the square with a side length of 4 cm, and tell you in disguise The height of this tin box is 4cm.

Question 2: "There's nothing to pay attention to, if you don't understand, you can ask."

Question 3: Do you understand that if there are two bottoms missing, isn't dividing by 2 just one bottom? A bottom surface is 4, the bottom surface is the edge length * edge length, so 4 = 2 * 2 is the edge length, the volume is the cube of the edge length, this is not 2 * 2 * 2, and the surface area needs 6 faces, 2 * 2 * is a bottom surface, 6 on * 6 OK, the landlord understands.

/4=192cm2 192/(32-2*4)=8cm

8+2*4=16cm 16*32=512cm2 The original area is 512 square centimeters.

20=500cm2 10*10*10=1000cm3 1000/500=2cm

15-2=13cm, water depth: 13cm, 2=4dm2, 4=2*2, the original edge length is 2dm, the surface area is 24dm2, and the volume is 8dm3

1.Description: Subtract 4cm to indicate that the height of the tin box is 4cm, the length is 32-4-4 = 24cm, the width is 768 24 4 = 8cm, the original area is 32 (8 + 2 4) = 512cm square.

2.(The total volume of water and iron is 25 20 15 = 7500cm cube) - (iron 10 10 10 = 1000cm cube) = 6500cm cube, 6500 25 20 = 13cm, and the water depth in the water tank is 13cm

3.8 is added and two faces are added, each face is 4dm square, and the cube side length is 2dm=20cm, the surface area is 4dm, and the volume is 8dm

Length: 32-8

Width: x-8 Height: 4: (32-8) * (x-8) * 4 = 768x = 16

I'll help you do a problem, and then you can do it yourself, you have to draw a diagram and use equations.

Solution: Let the sum of the speeds of A and B be x, then the whole process s is.

3x+120=(3+5)x-280

Solution x=80

So s = 3 80 + 120 = 360 (km).

A: The total distance is 360 km.

Another: Your question is not too strict, I guess a lot of words have been saved... For example, when A and B didn't meet, hehe, of course, this is just speculation).

The speed of the two cars and *3 hours + 120km = the speed of two times and *(3+5) hours - 280km

Let the distance be s and the column equation is (s+280) 8=(s-120) 3

s=360km

Your question is not too rigorous, I guess it saves a lot of words.

1) 18 cm = m 20 cm = m 30 cm = m.

cubic meters) cubic meters).

A: Xiao Xin's family produces about cubic meters of garbage every day.

2) cubic meters).

A: The total amount of garbage generated in a class in a day is about one square meter.

18 20 30 = 10,800 cubic centimeters 10,800 cubic centimeters = cubic meters.

cubic meters (the first question is done).

Question 2: Cubic meters.

The first empty is 60

The second empty is 148

1 Find the wire with a circumference of 60 cm.

2 Find the surface area 148cm2