8 、 13 、 10 、 1 1 、 12 、 9、——、 —— 。
23 、 24 、 20 、 12 、 17 、 6 、—— 、——。
2. Fill the nine numbers 1-9 in the box on the right, so that the sum of the numbers in each row, column and two diagonal lines is equal to 15.
Third, add appropriate operation symbols and brackets to make the equation hold.
9 9 9 9 9 = 12
9 9 9 9 9 = 20
4. Provisions: A *B = 3 × A+4 × B,
( 1)5*6 =( ) (2)(4*5)*8 =( )
5. The price of 80 Chinese books and 100 math books is equal, each Chinese book is 4 cents more expensive than the math book, and the price of each Chinese book is () yuan () cents.
6. An aquatic plant, which grows 1 times every day and covers the whole pond water surface for 30 days. It is the first day when it grows to half the surface of the pool.
7. What time is it on the wall clock? It takes 6 seconds for the clock to strike 4 o'clock and () seconds for the clock to strike 12 o'clock.
8. After subtracting 15 from Grandpa Li Gang's age, divide it by 4, subtract 6, and multiply it by 10, which is equal to 100. Grandpa Li Gang is () years old this year.
Nine, my cousin is older than Xiaoming 19 years old, just three years older than Xiaoming, 1 year old, Xiaoming () years old.
Ten, a row of small squares, each square is painted with one of two colors: red and black. When drawing a column (), at least two columns are the same (that is, one column is repeated with another).
XI。 How to divide the apples?
There are nine apples in the basket. Mother wants Xiaoling to send these apples to a nearby kindergarten and distribute them to nine children in a small class. A child has an apple, and there is one left in the basket at last. Xiaoling scratched her scalp and said to her mother, "How do you divide this?" How to divide it? Do you know that?/You know what? Do you know that?/You know what?
Twelve, two brothers buy books
There is a book that both brothers want to buy. Brother is short of 5 yuan, brother is short of 1 point. But two people buy books together, and the money is still not enough. Do you know the price of this book? How much money do they each have?
Thirteen, how many athletes are there?
Xiao Li just took part in a swimming competition not long ago. On the day of the rally, she shook hands with all the athletes who participated in the competition to show their friendship.
Xiao Li remembers that Yi * * shook hands fifty times. Do you know how many athletes participated in this competition?
Fourteen, the eggs in the basket
Put the eggs in a basket. Suppose the number of eggs in the basket increases by 1 time per minute, and so on. After 12 minutes, the basket will be full. So, do you know when it is half a basket of eggs?
Fifteen, a batch of toys
The kindergarten bought a batch of new small toys. 10 for each group, minus 2 points; If each group is 12, then you have just finished scoring, but you will lose one group. Please think about it. How many toys are there in this batch?
Sixteen, the passengers in the car
There are 54 passengers on a bus, starting from the starting station. At the first stop, eight people got off and two got on. At the second stop, 9 people got off and 3 people got on. At the third stop, five people got off and three got on. Children, do you know how many passengers are left in the car at this time?
Seventeen years old, father and son.
I know a child named Xiaolong, who loves learning very much. He always asks me to ask him questions. This day, he came to ask me questions again, and I said to him: We have a photo of two fathers's two sons at home. Can you guess how many people are in the photo? Xiaolong guessed at once. Have you guessed?
Eighteen, making pancakes
Three customers came to a store, eager to buy cakes to catch the train, and the limited time could not exceed 16 minutes. Several chefs said there was nothing they could do, because it took five minutes to bake two sides of a cake, and two cakes could be put in one pot at a time, so it took 20 minutes to bake three cakes. Then there was the chef Lao Li, who said that it only took 15 minutes to think. Do you know how to make a brand?
Nineteen, burning candles
There are 12 lighted candles on the table. First three were blown out by the wind, and then two were blown out by a gust of wind. Finally, how many candles are left on the table?
Twenty, clever queuing
Twenty-four people are arranged in six columns, and five people are required to be a column. Do you know how to arrange them?