1. It is known that one * *16 people need to cross the river, but there is only one boat by the river, and only four people can be there at a time; Choose one person as a sailor and take four people. After crossing the river, the sailor rowed the boat back to the shore, except for the sailor, who could only take three people. So when crossing the river for the first time, he took four people, leaving 12 people. Take three people across the river for the second time, leaving nine people; There were three people and six people crossing the river for the third time, three people crossing the river for the fourth time and three times crossing the river for the fifth time, and all the other three people were seated. So it takes five times to cross the river.
2. Mathematically, the simple formula is: after selecting the sailors, there are still 15 people left, and three people sit at a time. 15 divided by 3 equals 5.
The following are some statements about Divison in mathematics:
1, division is a basic operation in mathematics, which is divided into integer division, real division, matrix division and fractional division. Division is widely used in mathematics, physics, engineering and other fields.
2. Integer division refers to dividing two integers, and the quotient obtained is still an integer. For example, 10÷3=3 and 1, the quotient is 3 and the remainder is 1. Integer division is usually used to solve practical problems, such as calculating the number and time of objects.
3. Real number division refers to dividing two real numbers, and the quotient obtained is still a real number. For example, 8÷2=48÷2=4. Real division is also widely used in real life, such as calculation speed and length.
The Application of Division in Real Life
1. Allocating resources: In teamwork or family life, we often need to allocate resources according to the number of people or demand. At this time, division comes in handy. For example, if there is a cake to be distributed to five people, then we can calculate how many cakes each person can get by division. Divide the total weight of the cake by 5 to get the cake weight shared by everyone.
2. Distance calculation: When traveling or driving, we often need to calculate the time or mileage of the distance. For example, we have to drive from city A to city B, the distance between the two cities is 300 kilometers, and we are driving at a speed of 60 kilometers per hour, so we can calculate how many hours it takes to reach our destination by division. Divide the total distance by the driving speed to get the required time.