19966 ÷ 8 = 2495 R6
Let's divide 19966 by 8.

Step 1:
8 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 8

Step 2:
8 goes into 19 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 16 from 19 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 8

Step 3:
8 goes into 39 4 times with a remainder of 7.
Write down 4 as next digit of of the result. 
Result so far: 24
Subtract 32 from 39 to get 7.
Bring next digit (6) of the dividend behind the 7 and repeat the process: 76 / 8

Step 4:
8 goes into 76 9 times with a remainder of 4.
Write down 9 as next digit of of the result. 
Result so far: 249
Subtract 72 from 76 to get 4.
Bring next digit (6) of the dividend behind the 4 and repeat the process: 46 / 8

Step 5:
8 goes into 46 5 times with a remainder of 6.
Write down 5 as next digit of of the result. 
Result so far: 2495
Subtract 40 from 46 to get 6.

The final result is 2495 with a remainder of 6.