72102 ÷ 3 = 24034 R0
We're going to perform division on 72102 with 3 as the divisor.

Step 1:
3 goes into 7 2 times with a remainder of 1.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 6 from 7 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 3

Step 2:
3 goes into 12 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 24
Subtract 12 from 12 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 3

Step 3:
3 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 240
Subtract 0 from 1 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 3

Step 4:
3 goes into 10 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 2403
Subtract 9 from 10 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 3

Step 5:
3 goes into 12 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 24034
Subtract 12 from 12 to get 0.

The final result is 24034 with a remainder of 0.