Use 1, 2, 3 and 4 numbers to form a four digit number, in which each number is used once. What is the sum of all four non repeating digits like this

Use 1, 2, 3 and 4 numbers to form a four digit number, in which each number is used once. What is the sum of all four non repeating digits like this

According to the meaning of the title, there are 24 such four digits, because each digit appears six times in each position, then: the sum of the digits on the individual digit is: 6 × (1 + 2 + 3 + 4) = 60; the sum of the digits on the ten digit is: 6 × 10 × (1 + 2 + 3 + 4) = 600; the sum of the digits on the hundred digit is: 6 × 100 × (1 + 2 + 3 + 4) = 6000; the sum of the digits on the thousand digit is: 6 × 1000 × (1 + 2 + 3 + 4) = 60000; so the sum It is: 60 + 600 + 6000 + 60000 = 66660; answer: the sum of them is 66660

How many 3-digit numbers can be arranged from 0 to 9? It can be repeated. For example, 0
It can be repeated, such as 0 000 2 2 2 9 9, etc
Sweat! Look at the examples I gave! Brothers and sisters!

Because it can be repeated
There are 10 choices for individual, ten and hundred
So this combination is: 10 * 10 * 10 = 1000 kinds

0-9 digits form 4 digits, all combinations are repeatable
0-9 digits constitute 4-digit 5-digit 6-digit 7-digit 8-digit 9-digit all combinations, repeatable. It's better to see the result directly