21290 ÷ 3 = 7096 R2
Alright, let's work through the division of 21290 by 3 step by step.

Step 1:
3 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 / 3

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

Step 3:
3 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 70
Subtract 0 from 2 to get 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 3

Step 4:
3 goes into 29 9 times with a remainder of 2.
Write down 9 as next digit of of the result. 
Result so far: 709
Subtract 27 from 29 to get 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 3

Step 5:
3 goes into 20 6 times with a remainder of 2.
Write down 6 as next digit of of the result. 
Result so far: 7096
Subtract 18 from 20 to get 2.

The final result is 7096 with a remainder of 2.