The animal school held a children's song competition, with the elephant teacher as the referee.
The little monkey raised his hand first and began to recite: "I can calculate carry addition, and the digits can only be added if they are aligned." The number of digits should be aligned with the number of digits. When the number of digits exceeds ten, the number of digits should be advanced to ten. Add ten and one to count quickly and accurately. "
As soon as the little monkey finished speaking, the puppy began to recite again: "abdication and subtraction are not difficult, just align the numbers." If the single digits are small enough, ten people can borrow one. If ten people return, one will be ten, and if they return, one will be missing. How to reduce ten digits, ten digits will be reduced again and again. "
Everyone applauded their wonderful performance. Teacher elephant said, "Their children's songs make us understand that they both deserve to win the championship, right?" "Everyone agreed and congratulated them.
Second,
Bell's mother is ill. In order to earn money to treat her, Bear gets up before dawn every day to go fishing in the river and sell fish in the vegetable market as soon as possible.
One day, as soon as Little Bear set up the fish stall, the fox, the black dog and the old wolf came. When the bear saw a customer coming, he quickly called, "Do you want to buy fish? I just caught this fish. How fresh! " The fox asked, "How much is a kilo of such fresh fish?" The bear grinned: "Cheap, four yuan a kilogram." The old wolf shook his head: "I am old and my teeth are falling out." I just want to buy some fish. " Bear was reluctant: "I'll sell you the fish." Who do I sell the fish head and tail to? " The fox wagged his tail and said, "Yes, no one wants to buy the leftovers, but Uncle Wolf has bad teeth and can only eat some fish. Guess what? Black dog and I are good at each other's teeth. One of us buys fish heads and the other buys fish tails. Didn't you help Uncle Wolf and Brother Xiong? "The bear clapped his hands, but he hesitated." Good, but at what cost? "The fox rolled his eyes and replied," 2 yuan is 1 kg, head and tail are 1 yuan is 1 kg. Isn't that 4 yuan 1kg? "The bear drew a picture on the ground with a stick, and then patted his thigh:" OK, let's start! "! " Four people, Qi Xin, worked together, and in a short time, the fish head, tail and body were separated. Xiong Yi said that the fish body is 35 kilograms of 70 yuan; Fish head 15 Jin 15 yuan, fish tail 10 Jin 10 yuan. The wolf, the fox and the black dog quickly ran to the Woods with the fish, matched the fish head, the fish body and the fish tail, and then divided them equally. ...
On the way home, Bear thought: According to 4 yuan 1 kg, I should sell 60 kg of fish to 240 yuan, but now I only sell 95 yuan ... Bear can't figure it out.
Clever students, do you know what this is all about?
Third,
In 46 BC, Julius Caesar, commander-in-chief of Rome, specified the calendar. Because he was born in July, in order to show his greatness, he decided to change July to "Julian month", and all single months were stipulated as 3 1 day, and bimonthly was 30 days. In this way, there is one more day in a year. February was the month when prisoners were executed in ancient Rome. In order to reduce the number of people executed, 1 day was reduced in February to 29 days.