1. The diameter of a hair is about 0.06 mm. It is accurate to () and has () significant digits 2. Use the rounding method to approximate the numbers in the following examples according to the requirements in brackets: (1) 365 (accurate to percentile); (2) 1.567 (accurate to 0.1); (3) 38.82 (accurate to individual); (4) 2435429 (keep 3 significant digits); (5) 18.07 (keep 1 decimal place) 3. The approximate number 7.80 obtained by rounding is accurate to which bit? It represents the number greater than or equal to and less than? 4. According to statistics, the number of PHS and SMS users in a certain area has reached 11910000 (1) Accurate to ten thousand; (2) accurate to one million; (3) accurate to ten million 5. Last year, the total import volume of high-tech products in a certain place was 528.78 billion US dollars, an increase of 30% over the previous year. If this proportion is still increased this year, how many billion US dollars can the import and export volume of high-tech products reach this year? 6. The approximate number 37.5 obtained by rounding is accurate to () bit, which means the number greater than or equal to () but less than () 7. Use scientific counting to represent the larger number in the following example: (1) According to statistics, about 300 cities across the country are short of water, with a monthly water shortage of about 15 million tons; (2) Daxinganling is a famous mountain range in Northeast China. It starts from the Bank of Heilongjiang River in the north and reaches the valley of xilinmu River in the south 9. For a rectangular piece of paper with an area of 1 square meter, cut half of it in the first time and the remaining half in the second time. If you cut it like this, what is the area of the remaining piece of paper after the sixth time? 10. An investigation team started from the camp by car at 8 a.m. with an average speed of 50 km / h. The car drove East for 40 km, worked for 30 minutes, then drove West for 2.5 hours, worked for 1 hour, and then drove East all the time?

1. The diameter of a hair is about 0.06 mm. It is accurate to () and has () significant digits 2. Use the rounding method to approximate the numbers in the following examples according to the requirements in brackets: (1) 365 (accurate to percentile); (2) 1.567 (accurate to 0.1); (3) 38.82 (accurate to individual); (4) 2435429 (keep 3 significant digits); (5) 18.07 (keep 1 decimal place) 3. The approximate number 7.80 obtained by rounding is accurate to which bit? It represents the number greater than or equal to and less than? 4. According to statistics, the number of PHS and SMS users in a certain area has reached 11910000 (1) Accurate to ten thousand; (2) accurate to one million; (3) accurate to ten million 5. Last year, the total import volume of high-tech products in a certain place was 528.78 billion US dollars, an increase of 30% over the previous year. If this proportion is still increased this year, how many billion US dollars can the import and export volume of high-tech products reach this year? 6. The approximate number 37.5 obtained by rounding is accurate to () bit, which means the number greater than or equal to () but less than () 7. Use scientific counting to represent the larger number in the following example: (1) According to statistics, about 300 cities across the country are short of water, with a monthly water shortage of about 15 million tons; (2) Daxinganling is a famous mountain range in Northeast China. It starts from the Bank of Heilongjiang River in the north and reaches the valley of xilinmu River in the south 9. For a rectangular piece of paper with an area of 1 square meter, cut half of it in the first time and the remaining half in the second time. If you cut it like this, what is the area of the remaining piece of paper after the sixth time? 10. An investigation team started from the camp by car at 8 a.m. with an average speed of 50 km / h. The car drove East for 40 km, worked for 30 minutes, then drove West for 2.5 hours, worked for 1 hour, and then drove East all the time?

1. Percentile 1
2.0.37 1.6 39 2.44 18.1
3. Percentile
……………
Too much. It's annoying

If you arrange the positive and even numbers into five columns according to the above table, which row and column should 2008 be in?
First column second column third column fourth column fifth column
First line 0 2 4 6 8
The second line 16 14 12 10 8
The third line 16 18 20 22 24
Urgent, urgent, urgent

Line 251 column 5
/*HTML programming, the following code, can be directly assigned to run*/
Var arr = new array(); / / array
Var a = new array(); / / row (subarray)
var i = 0,j = 0;
var b = true;
do {
a = new Array();
if (j > 4)
j = 0;
for (; j < 5; j++) {
If (I = = 0) {/ / first line
if (j == 0)
a.push(0);
else
a.push(a[j - 1] + 2);
}
If (I > 0 & & I% 2 = = 1) {/ / odd rows
if (j == 0)
a.push(arr[i - 1][4]);
else
a.splice(0,0,(a[0] + 2));
}
If (I > 0 & & I% 2 = = 0) {/ / even rows
if (j == 0)
a.push(arr[i - 1][0]);
else
a.push(a[j - 1] + 2);
}
if (a[j] >= 2008)
b = false;
}
i++;
arr.push (a) ; / / add rows to array
}
while (b);
Alert ("row" + I + ", column" + j + ", arr [" + (I - 1) + "] [" + (J - 1) + "]:" + arr [I - 1] [J - 1]);
Alert ("the" + I + "behavior" + arr [I - 1]);

What are the multiples of 2, 5 and 3 within 100?

There are 30, 60 and 90. The natural number with 0 or 5 at the end is a multiple of 5. The natural number with 0, 2, 4, 6 and 8 at the end is a multiple of 2. Add up the numbers in each digit of a number. If it is a multiple of 3, then the number is a multiple of 3. Therefore, if it is a multiple of 2 and 5, there are only 10, 20, 30, 40, 50, 60, 70, 80 and 90

Sixth grade volume 1 of a mathematical problem, give 100 points
What's the percentage of five days in September? What's the percentage of 18 days in September?

.
September has 30 days. 5 / 30 = 1 / 6 is one sixth
18 / 30 = 3 / 5 is three fifths

There are ten red, yellow, blue and purple balls, which are mixed in a closed box (can't be seen). At least a few balls can be found at a time to ensure two balls
Question 2: 24 puppies return to 7 cages, at least several puppies enter the same cage? Why?

① If you have a question, how about two balls? Are they two colors or are the two balls the same color? If they are two colors, that's at least 11, because it's possible that the first 10 balls are the same color. If they are the same color, that's at least 5, because the first four balls are different, but the fifth one must go back to the previous one and repeat the color
② That is to say, there are at least 3 dogs in each cage, and there are at least 4 dogs in at least three cages. Only in this way can we ensure that the number of dogs in all cages is the largest, the number of cages is the lowest, there are 4 dogs, and the number of cages is 4

What is x + 1 / 2 = x + 1 / 4 - 1?

x=1

1. Cut a cube with a volume of 64 cubic centimeter from a cuboid with a length of 6 cm. The original surface area of this cuboid is () square centimeter
2. Divide a number by 10 and 54, and the quotient is exactly an integer. The maximum of this number is ()
3. A minimalist fraction, if the numerator plus one equals two fifths, if the numerator minus one equals one fifths, the minimalist fraction turns out to be ()
4. Four fifths of the mass of a steel is equal to a fraction of the mass of the same steel ()
5. The sum of five continuous natural numbers is 200, and the largest one is ()
six

1. According to the conditions, the height and width of the cuboid are 4 cm (4 × 4 × 4 = 64). So the surface area of the original cuboid is (4 × 4 + 4 × 6 + 4 × 6) × 2 = 128 (square cm) (the original meaning of "section" in this question is to cut it parallel to a certain plane of the cuboid)

Senior high school number calculation, if satisfied, send points
When winding a ribbon product, the radius of the winding shaft (mandrel) is a, the thickness of the product is B, the length of the product is C, and how many turns should be wound n

The radius of the first circle is a + B / 2, and the perimeter A1 = 2 π (a + B / 2)
Radius of the nth cycle - (radius of n-1 cycle) = B, perimeter an-a (n-1) = 2 π B
Circumference is an arithmetic sequence: the first term A1 = 2 π (a + B / 2) tolerance d = 2 π B
The first n terms and Sn = C
Sn=a1+(n-1)d/2=2π(A+B/2)+(n-1)πB=2πA+nπB=C
n=(C-2πA)/πB

4.3 cubic decimeter___ Cubic decimeter___ CC 538 & nbsp; ml___ CC & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 20 seconds = -___ Points

(1) 3 cubic decimeter = (4) cubic decimeter (300) cubic centimeter; (2) 538 ml = (538) cubic centimeter; (3) 20 seconds = (13) minutes

There is a question of grade one in junior high school. There is a reward,
Two objects move on a circle with a circumference of 400cm. If they move in the same direction, they meet every 20 seconds. If they move in the opposite direction, they meet every 10 seconds. Find the speed of each object. If the faster moving speed of the two objects is xcm and the slower moving speed is YCM, then according to the meaning of the title, we can get the equations as ()
Please indicate the process and why

400/(x-y)=20
400/(x+y)=10
x=30m/s
y=10m/s