"The difference between unit" 1 "and natural number 1"

It is the difference between number and quantity;
Unit 1 is quantity (dimension);
The natural number 1 is a number
Number and quantity together can express a complete feature;
For example: a person is 100kg; / * OK, make clear the weight of the person*/
You only need to count: this person weighs 100; / * others don't know whether it's 100 Jin or 100 kg*/
Or: this person weighs kg; / * others don't know anything*/

What is natural number in mathematics book

It is used to measure the number of things or to indicate the order of things The number that represents the number of objects is called natural number. Natural number starts from 0 (including 0), one by one, forming an infinite collective

Is the range of N in mathematics a natural number, a positive integer or an arbitrary number
What range does n represent when people say 2n + 1

The general expression is integer
There is no difference between positive and negative
You have to explain yourself

The number of girls in Zuxin leather shoes factory is 150 less than 75% of the total number of employees, and the number of boys accounts for 60% of the number of girls?

Suppose the male is x and the female is y
Y=（X+Y）×0.75-150
X=0.6Y
Find X and y
X=450
Y=750
So the total number is x + y = 1200

If | x-3 | + (2Y + 4) 2 = 0, then XY equals 0___ ．

The solution is x = 3, y = - 2, so xy = 3 × (- 2) = - 6

5、 There are 52 students in class 2 who have reached the standard of physical education in the last semester, of which 28 are boys. How many of them are boys and girls?

A: the number of boys reaching the standard is 712, and the number of girls reaching the standard is 512

Let the real numbers x and y satisfy the equation 2x2 + 3y2 = 6y, then the maximum value of X + y

The formula is: 2x ^ 2 / 3 + (Y-1) ^ 2 = 1
Parameter method: x = acost, y = 1 + Sint, a = √ (3 / 2)
Therefore, x + y = acost + 1 + sin = 1 + √ (a ^ 2 + 1) sin (T + P) = 1 + √ (5 / 2) sin (T + P), where p = arctana
So the maximum value is 1 + √ (5 / 2)

The number of sixth grade students participating in the school winter sports meeting is 140, and the ratio of the number of girls to boys is 3:4. How many boys and girls each participate in the sports meeting?

Let X be the ratio
Then 3x + 4x = 140
x =20
So girl: 3 times 20 = 60
Male: 4 × 20 = 80

A number is 56. What is the reduction of 52% after reducing one number? Six times of a number minus six equals 75% of 24. What is the number?
What's 20% of a number?
32+75%x=56
32+75%x=8

What's 20% of a number?
（1+20%）x=120
The solution is x = 100
20% of 100 = 20
Six times of a number minus six equals 75 percent of 24. What's the number?
6x-6 = 24 * 75% (* stands for multiplication sign)
The solution is x = 4

The average number of a, B and C is 80, and the ratio of the three numbers is 1:2:3 、、__ ．

80 × 3 = 2401 + 2 + 3 = 6 A: 240 × 16 = 40 B: 240 × 26 = 80 C: 240 × 36 = 120 so the answer is: 40, 80120

"The difference between unit" 1 "and natural number 1"