65999 ÷ 3 = 21999 R2
We're going to perform division on 65999 with 3 as the divisor.

Step 1:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 6 from 6 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 3

Step 2:
3 goes into 5 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 21
Subtract 3 from 5 to get 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 3

Step 3:
3 goes into 29 9 times with a remainder of 2.
Write down 9 as next digit of of the result. 
Result so far: 219
Subtract 27 from 29 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: 2199
Subtract 27 from 29 to get 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 3

Step 5:
3 goes into 29 9 times with a remainder of 2.
Write down 9 as next digit of of the result. 
Result so far: 21999
Subtract 27 from 29 to get 2.

The final result is 21999 with a remainder of 2.