21372 ÷ 7 = 3053 R1
We're going to perform division on 21372 with 7 as the divisor.

Step 1:
7 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 7

Step 2:
7 goes into 21 3 times with a remainder of 0.
Write down 3 as next digit of of the result. 
Result so far: 3
Subtract 21 from 21 to get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 7

Step 3:
7 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of of the result. 
Result so far: 30
Subtract 0 from 3 to get 3.
Bring next digit (7) of the dividend behind the 3 and repeat the process: 37 / 7

Step 4:
7 goes into 37 5 times with a remainder of 2.
Write down 5 as next digit of of the result. 
Result so far: 305
Subtract 35 from 37 to get 2.
Bring next digit (2) of the dividend behind the 2 and repeat the process: 22 / 7

Step 5:
7 goes into 22 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 3053
Subtract 21 from 22 to get 1.

The final result is 3053 with a remainder of 1.