The search pattern is a common theme in the o number of subjects, divided mainly into the search patterns and the search patterns. Teacher wang has prepared a special exercise on mathematics for the sixth grade
Classic case
Example 1: find a regular number。
(1) 1, 3, 5, 7, ( ), ( )。
(2) 65, 60, 55, 50, ( ), ( )。
(3) 1, 10, 100, 1000,( ),( )。
(4) 1, 2, 4, 7, 11,( ),( )。
(5) 1, 2, 4, 8,(),()。
(6) 1, 3, 4, 7, 11, ( ), ( ), ( ), ( )。
Think about it
Question (1), increased from left to right; question (2), reduced from left to right; question (3), added one at the end from left to right, or multiplied in turn; question (4), from left to right, varied by 1, 2, 3, 4 ... Question (5), 1 x 2 = 2, 2 x 2 = 4, 4 × 2 = 8, so that in question (6), from the third number, each number equals the sum of the first two。
Imitation practice
Find a regular number。
(1) 2, 4, 6, 8,( ),( )。
(2) 1, 5, 9, 13,( ),( )。
(3) 2,20,200, 2000,(),()。
(4) 1, 2, 2, 4, 3, 6, 4, 8,( ),( )。
(5) 49, 42, 35,(),(),(),()。
(6) 4, 6, 9, 13,( ), 24,( )。
(7) 100, 81, 64, ( ) 36, 25, ( ) 9, 4, 1
Example 2: take a closer look at the following group figure and fill in the appropriate number in the "?" for each group。
(1)
(2)
(3)
(4)
(5)
Think about it
In question (1), 3+4+8=15; in question (2), 2x3+1=7; in question (3), 3x4+5=17; in question (4), 4x5-5=20; and in question (5), 5+3+7=15,15+15=30。
Imitation practice
Carefully observe the pattern of each set and fill out the appropriate number in the blank。
(1)
(2)
Example 3: fill in the appropriate number at the empty。
Think about it
Analysis of the numbers in the table shows that 12+6 = 18, 8+7 = 15 by row, i. E. The number at the middle of each line equals the sum of two on both sides. This pattern allows you to fill out the number of spaces。
Find a regular exercise
1. The 25th graphic is according to the pattern of the drawings below (script drawing)
I'm sorry
2. Take a closer look at the figure below, and imagine what graphics should be added to the third chart question mark
3. Take a closer look at the graphics below and think about what the fourth one should look like
4. In accordance with the pattern of changes in the three maps presented below, the shadows appear in the fourth
Consider how many small dots should be in the box
Draw consistent graphics at '?' according to the pattern of graphs
The order of the observation chart, with appropriate graphics in "?"
Which of the next graphics is different from the other graphics, find out, and put on the tack
Look at the pattern of black and white balls, and then answer the question, how many white balls and how many black balls are in the box
Four little animals sit in seats, as follows: at first, mice sit on number 1, monkeys sit on number 2, rabbits sit on number 3, cats sit on number 4. After that, they exchanged seats several times: for the first two rows, for the second, for the second, for the third, for the second row, for the fourth, for the second row, for the fourth row, for the second row, and for the second row, for the second row
Answer parsing
1
Tips: the graphics that appear in this column are squares, triangles, circles, and the pattern of three graphics is four sets of cycles in the order of squares, round triangles. Since 25÷4=6... 1, the first graphic, square, should be added to the line
2
Note: the first two groups of graphics to be observed show that the first and second groups are made up, but in different order. Two of the left in the first group become two of the right in the second group, while the other three are moved to the left in the original order
3. Caution: the first three images are made up of large circles, the first one rotates in reverse-clockwise direction, the second one rotates in reverse-clockwise direction, and the third, the same as the fourth
4. Note: the shadows of the first chart are rotated in the direction of a clockwise, and the shadows of the second are rotated in the direction of a clockwise, so that the shadows of the third map are rotated in the direction of a clockwise, so that the fourth figure is obtained
5. 25 dots should be filled in the box
6. Note: the first three images of the observation show that the first one is rotated in reverse timewise direction and the next one is available
7
Note: as can be seen from the observation, the number of lines from top to bottom is reduced by one and the number of triangles is increased by one each, thus pushing the graphics of the "?" section
8.(1) tip: the common feature of geometric graphics in the diagram is that there is one of the same types of graphics in the graphics. But the internal graphics in 1, 3, 4 and 5 are smaller, there are only two large internal graphics and there are different positions
(2) tip: these five graphics are made of the same two graphics, but the difference is that the first four graphics are covered by the next four graphics, only five different, and the top one covers the next
9. 9 white balls, 3 black balls
Note: as you can see, black and white balls are organized according to the pattern of two black balls, one white ball, two black balls, three white balls, two black balls, five white balls... I. E., two black balls in each group, and the number of white balls is increased by 2
10. Rabbit in position 2
Caution: rabbits start at position 3, and after the fourth exchange, the rabbit returns to position, so that the tenth exchange of rabbits is the same as the second exchange, because 10 ÷4 = 2 ... 2
