Shells have four numbers, and the last one is more: 4,8, 12,16,20,24, …
Five numbers of five, and finally there are two: 5, 10, 15, 20, 25, 30, …
Six numbers of six, the last three: 6, 12, 18, 24, 30, 36, …
It can be observed that the differences of each sequence are 4, 5 and 6 respectively. Therefore, in the next sequence, the law of increasing numbers of 4, 5 and 6 still holds. According to the requirements of the topic, there should be four numbers in the next series, so the next series should be: 28, 32, 36, 40, 44, 48, …
For the last time, you will find:
Four numbers of four: 4,8, 12,16,20,24,28,32,36,40,44,48 (* * *12).
Five numbers of five: 5, 10, 15, 20, 25, 30 (* * 6).
Six numbers of six: 6, 12, 18, 24, 30, 36 (* * 6).
According to the requirements of the topic, the last four numbers are 12, the five numbers are six, and the six numbers are six.
When solving the problem of finding the law, we should pay attention to observing the law of sequence or sequence, paying attention to common mathematical operations and patterns, thinking from multiple angles, and trying recursion and iteration.
1. Observe the sequence or the law of the sequence: carefully observe the given sequence, and pay attention to the number, order, increase and decrease law, etc. Finding the relationship between numbers in a series is the key to finding the law.
2. Pay attention to common mathematical operations and modes: There are often some common mathematical operation modes in the series, such as arithmetic progression (the difference of numbers is equal) and geometric progression (the ratio of numbers is equal). Looking for these rules can help you find them.
3. Multi-angle thinking: Try to think from different angles and ways and observe different aspects of the series. We can consider the properties of numbers such as single digits, tens digits and hundreds digits, and also consider the characteristics of parity, prime number and square number in a series.
4. Try recursion and iteration: sometimes, the law of a series may depend on the previous number. At this time, you can try recursive or iterative relationship to calculate subsequent items through known items.