20842 ÷ 7 = 2977 R3
We're going to perform division on 20842 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 (0) of the dividend behind the 2 and repeat the process: 20 / 7

Step 2:
7 goes into 20 2 times with a remainder of 6.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 14 from 20 to get 6.
Bring next digit (8) of the dividend behind the 6 and repeat the process: 68 / 7

Step 3:
7 goes into 68 9 times with a remainder of 5.
Write down 9 as next digit of of the result. 
Result so far: 29
Subtract 63 from 68 to get 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 7

Step 4:
7 goes into 54 7 times with a remainder of 5.
Write down 7 as next digit of of the result. 
Result so far: 297
Subtract 49 from 54 to get 5.
Bring next digit (2) of the dividend behind the 5 and repeat the process: 52 / 7

Step 5:
7 goes into 52 7 times with a remainder of 3.
Write down 7 as next digit of of the result. 
Result so far: 2977
Subtract 49 from 52 to get 3.

The final result is 2977 with a remainder of 3.