What is a percentage?
A number indicating that one number is a percentage of another number is called a percentage. Percentage is also called percentage or percentage.
The meaning of percentage and fraction
Percentages and scores are not exactly the same. Fraction can represent the fraction of a number in the unit "1" or a number, but percentage cannot represent a number. Therefore, percentages cannot be expressed in units.
The significance score of percentage can represent a score or a number. When representing a number, you can have the name of the unit of measurement (this is the main difference between the two); When expressing scores, you can't talk to any company name.
Percentage only represents percentage, and it cannot be followed by any company name.
Percent means that one number is a percentage of another. Percent is also called percentage or percentage. Percentages are usually not written in the form of fractions, but are represented by the symbol "%"(called percent sign). If it is written as 4 1%, 1% is 0.0 1. Because the denominator of the percentage is 100. Percentage is widely used in industrial and agricultural production, science and technology and various experiments, especially in investigation, statistics, analysis and comparison.
Although the denominator of the percentage is 100, the numerator can be greater than 100, for example, 200% means twice the original number. For example, a company's net profit last year was 6.5438+0.2 million yuan, and this year's net profit was 6.5438+0.2 million yuan, which can be expressed as "this year's net profit increased by 20% compared with last year" or "this year's net profit increased by 654.38+0.20% compared with last year", but this writing method is rarely used. Percentages are sometimes misleading. Many people think that an increase in percentage will be offset by a decrease in the same percentage. For example, a 50% increase in 100 equals 100+50, that is, 150. And a 50% reduction from 150 is 150-75, which is equal to 75. The final result is less than the original number 100. The numerator of percentage can also be decimal.
The formation of the concept of percentage should be based on the examples in students' real life or industrial and agricultural production. For example, there are 100 students in senior one, among whom 47 are girls, accounting for 47% of the whole grade and 47% of the writing. For example, there are 200 senior two students, including girls 100, accounting for 50% of the whole grade. The number of students in two grades is "standard quantity", while the number of girls is "comparative quantity". In the teaching of percentage application problems, we should grasp the quantitative relationship = percentage (percentage) for analysis.
The application of percentage in daily life
The weather forecast program on TV will broadcast the weather situation and precipitation probability of that night and tomorrow day every day, prompting everyone to prepare in advance, just like the precipitation probability of tonight is 20%, and there will be a strong wind of 5 ~ 6 in the daytime tomorrow, and the precipitation probability is 10%, so you should add clothes sooner or later. 20% and 10% are clear and concise.
With the rapid development of science and technology, every middle-aged person is now equipped with various styles of mobile phones. Glenn Wilson, a psychologist at Royal College, University of London, has proved that reading short messages with his head down all the time will lead to low work efficiency and slow down the brain reaction ability of staff, and the IQ of people who read short messages often will drop by 10%, which once again proves in percentage form that although mobile phones provide convenience for people, they are very harmful to human health.
This is the information about percentage that I found in my life. I believe that as long as you observe carefully, you will also find that percentage is everywhere in your life.
80%
China is the largest producer of energy-saving lamps in the world, but 80% of its products are exported, and the domestic consumption is seriously low.
47. 1%
According to 200 1 undergraduate and junior college students, 47. 1% of the contracted college students have a monthly salary below 1500 yuan.
85.53%
According to an online survey, 85.53% of netizens have never read a famous book in recent years. In addition, 8.58% netizens have never read a famous book in the past ten years, and 6.75% netizens said that they have never read a famous book.
Percentage application problem
There are three calculation problems in the application of percentage: ① Find the percentage of one number to another, for example, find the percentage of 45 to 225, that is, = 20%; ② Find the percentage of a number; For example, find 75% of 2.2, that is, 2.2× 75% =1.65; 3 know one.
A number indicating that one number is a percentage of another. Percentages are also called percentages or percentages. Percentages are usually not written in the form of fractions, but are represented by the symbol "%"(called percent sign). For example, write 4 1% and 1% respectively. Since the denominator of percentages is 100, they are all 65438+.
Expansion and improvement:
1. A number indicating that one number is a thousandth of another number is called one thousandth, and one thousandth is also called thousandth rate. Like a percentage, one thousandth has a micron.
2. The internal relationship between percentage and fraction: both can express the multiple relationship of two quantities.
3. The difference between percentage and fraction: (1) has different meanings, and percentage only indicates the multiple relationship between two numbers, and it cannot be accompanied by the company name; The score can represent a specific number or the relationship between two numbers, and the specific number can be represented by the company name. (2) Percentages can be integers or decimals; The numerator of a fraction cannot be a decimal, but only a natural number other than 0; Percentages cannot be reduced, but fractions are generally divided into the simplest fractions by reduction. (3) Any percentage can be written as a fraction with a denominator of 100, and fractions with a denominator of 100 do not all have the meaning of percentage. (4) Different application ranges, percentage reproduction and life span are often used for investigation, statistics, analysis and comparison, while scores are often used when the results in calculation and measurement are less than integers.