21668 ÷ 7 = 3095 R3
Let's divide 21668 by 7.

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 (6) of the dividend behind the 0 and repeat the process: 6 / 7

Step 3:
7 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 30
Subtract 0 from 6 to get 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 7

Step 4:
7 goes into 66 9 times with a remainder of 3.
Write down 9 as next digit of of the result. 
Result so far: 309
Subtract 63 from 66 to get 3.
Bring next digit (8) of the dividend behind the 3 and repeat the process: 38 / 7

Step 5:
7 goes into 38 5 times with a remainder of 3.
Write down 5 as next digit of of the result. 
Result so far: 3095
Subtract 35 from 38 to get 3.

The final result is 3095 with a remainder of 3.