1,3,8,21,55 () () fill in the numbers according to the rules. How can the third grade explain to the children
Multiply a number by 3 and subtract the number before it = the number after it
1、3、8、21、55、144、377
The latter number multiplied by 3 minus the former number equals the next number
3*3-1=8
8*3-3=21
21*3-8=55
55*3-21=()=144
144*3-55=()=377
The two numbers in () are 144377