First, clever use of the unit "1"

Example 1. There are 2000 workers in two factories. If factory A transfers the original workers and factory B transfers 1 10, then the number of people left in the two factories is equal. How many former workers are there in the two factories?

Exercise:

1. Fruit to apple and pear * * *1300kg. After the apples are sold out and the pears are sold for 20 kilograms, the remaining pears and apples weigh exactly the same. How many Jin of apples and pears were originally sent?

There are 250 books on science and literature in the library of class 2.6/kloc-0. If science and technology books are lent out, there are five more books than literature and art books. How many scientific and literary books are there?

3. There are red and yellow balls *** 140. Take out the red ball and seven yellow balls, and there are as many red balls and yellow balls left. How many red and yellow balls are there?

Example 2: The sum of numbers A and B is 2 10, and number A equals number B. What are numbers A and B?

Exercise:

1, the sum of the two numbers is 1 15. If the number of A equals the number of B, what are the numbers of A and B respectively?

2. The difference between number A and number B is 80, and number A equals number B. What are the numbers A and B respectively?

The number of peach trees is equal to the number of pear trees. Two kinds of fruit trees are 14 1 plant. How many trees are there in each kind?

Example 3: There are 300 young pioneers in Grade One and Grade Two in a school, and there are 55 more young pioneers in Grade Two than in Grade One. How many pedestrians are there in each grade?

Exercise: 1 school *** 100 There are basketball and football, and basketball is more than football 16. How many basketballs and footballs are there?

Master and apprentice made 840 parts. The master processed 60 more parts than the apprentice. How many pieces did the master and apprentice process respectively?

The school library bought 600 new books. The number of novels is 58 more than that of historical geography books. How many books did you each buy?

Example 4: There are two grain depots, A and B. The tonnage of grain stored by the former belongs to the latter. For example, the 6 tons transferred from grain depot B to grain depot A is very memorable. How many tons of grain are stored in Grain Depot A and Grain Depot B respectively?

1.The original number of team B belongs to team A. Now team A sends 30 people to team B, so the number of team B belongs to team A. How many people are there in teams A and B?

2. Party A and Party B collect stamps. The number of stamps of Party A is B. If Party B gives Party A 10 stamps, the number of stamps of Party B is A..A How many stamps are there in A and B?

My brother's deposit belongs to my sister. My sister gave my brother 3 yuan money, and the amount of money saved by my brother was my sister's. How much money did the two brothers and sisters originally save?

Example 5: When gold is put into water, the weight is reduced; When silver is put into water, the weight is reduced; An alloy weighing 770g was put into water, and the weight was reduced by 50 g. How many grams of gold and silver does this alloy contain?

Exercise:

1. A middle school enrolled 750 students last year. This year, the number of boys has increased while the number of girls has decreased. This year, * * * enrolled 7 10 students. How many boys and girls are enrolled in school this year?

2. There are 1 19 workers in a workshop. As a result of the reform, the number of male workers has increased and the number of female workers has decreased. There are 12 1 workers in the workshop here. How many men and women are there in this workshop?

The library of our school bought 475 books on science and technology last year and 640 books on science and literature this year. Among them, science and technology books increased by 48% compared with last year, and literature books increased by 20%. How many science and literature books are there in the new book bought this year?

Example 6: The bag contains red and yellow balls, and the number of red balls is yellow. Later, two red balls were released and three yellow balls were taken out. At this time, the number of the red ball is yellow. How many red balls and yellow balls are there in the schoolbag now?

Exercise: 1 The number of people in Workshop A is four. Later, there were 20 employees in Workshop A and 35 employees in Workshop B.. At this time, the number of people in Workshop A is four. How many workers are there in each workshop?

2. There are a bunch of Weiqi, and the sunspot belongs to Bai Zi. Now, if you remove 12 sunspots and add 18 albino stars, the number of sunspots comes from Bai Zi. How many albinos and sunspots are there now?

Xiaoling's original book number is small square. On Children's Day on June 1st this year, after the teacher bought 20 books and distributed them to two people equally, Xiaoling's books were Xiao Fang's. How many books does Xiaoling have now?

Example 7: The number of boys in the school math interest class accounts for the total number of math interest classes. Later, 20 boys joined. At this time, boys accounted for the total number of math interest classes. How many boys and girls are there in the math interest class?

Exercise: 1 There is a pile of sweets, among which milk sugar accounts for. After adding 16 piece of fruit candy, milk candy accounts for. How many pieces of toffee are there in this pile of candy?

The school bought a batch of flowers to beautify the campus. Among them, the number of pots of Chinese rose flowers accounted for 45% of the total, and later I bought 16 pots of other flowers. At this time, the number of pots of Chinese rose flowers accounts for 25% of the total. How many pots are there between Chinese rose and other flowers now?

Among the students reading in the reading room, girls account for 50%. After five girls walked out of the reading room, the proportion of girls in the reading room. How many boys and girls are there among the students reading books?

Example 8: There are two candles, one is 8 cm long and the other is 6 cm long. After they are fired to the same length, the short remaining length is the long remaining length. How many centimeters is each burn?

Exercise 1. There are two ropes, one is 80 meters long and the other is 40 meters long. If the same length is cut from each of the two ropes, the remaining length of the short rope is left. How many meters each?

There are 40 books on the upper floor and 30 books on the lower floor. After taking the same number of books from two shelves, the books on the lower shelf are the same as those on the upper shelf. How many books are there on each shelf?

The goods stored in two warehouses A and B have the same weight. 800 tons of goods are shipped from warehouse A, 500 tons from warehouse B, and the remaining tonnage of warehouse A is the remaining tonnage of warehouse B ... How many tons are the original orders of warehouse A and warehouse B?

Example 9: A pile of coal was shipped 30 tons more for the first time, 10 tons for the second time, and 120 tons for the third time, which has just been shipped out. How many tons is this pile of coal?

Exercise: 1, road construction. The total length of the first day was 60 meters more, and the second day was 35 meters more than the first day. How long is this road?

2. build a road. On the first day, the total length was increased by 20 meters, and the rest was repaired the next day, leaving 86 meters. What is the total length of this road?

Xiao Zhang bought some oranges. On the first day, he ate 1 orange, and the next day, he ate the remaining two oranges. There are 14 oranges left. How many oranges did Xiao Zhang buy?

Example 10: The school interest classes are divided into two groups, from group A to group B, and then from group B to group A. At this time, there are 24 students in the two groups at the earliest. How many students are there in each group?

Exercise 1, Wang Xiaoli is collecting stamps, Xiaolin takes out some of her own stamps for Xiao Li, and Xiao Li takes out her existing stamps for Xiao Lin. At this time, each of them has 12 stamps. How many stamps does each of them have?

2. There are several workers in Workshop A and Workshop B. The number of workers transferred from Workshop A to Workshop B, and then transferred from the current number of workers in Workshop B to Workshop A. At this time, there are 90 workers in both workshops. How many people are there in these two workshops?

3, a car full of watermelons, sold for the first time, and then added 40 Jin. If the watermelon in the car is sold for the second time, it will be sold for the third time 180 kg. At this time, there are 60 kilograms of watermelons in the car. How much does this watermelon weigh?

Example 1 1: the average price of a certain type of children's clothing 1 15 yuan, in which men's clothing is more than women's clothing, and women's clothing is more expensive than men's clothing on average 10%. What is the average price of men's wear in these children's clothes?

Exercise: 1, the number is the number of girls. Average height of boys 138 cm, average height of the whole class 132 cm. What is the average height of girls in centimeters?

2. The men's size of a garment is the women's size. On average, women's clothing is more expensive than men's clothing 15%, and the average clothing price for men and women 130 yuan. How much are men's and women's clothes on average?

3. The average score of an exam in one class is 80 points. Among them, the average score is 85. Among the students who pass and flourish, what is the average score of the students who fail?