We look at the division of 77490325 by 639 
We're looking to find how many times 639 goes into 77490325.

Moving on to step 1:
7 divided by 639 is 0 with a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Bring next digit (7) of the dividend behind the 7 and repeat the process: 77 / 639

Moving on to step 2:
639 can be fit into 77 0 times, resulting in a remainder of 77.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 77 to get 77.
Take the next digit (4) from the dividend and append it to 77, then repeat: 774 / 639

Let's proceed to step 3:
The number 639 fits into 774 1 times, leaving a remainder of 135.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 639 from 774 leaves us with 135.
Bring next digit (9) of the dividend behind the 135 and repeat the process: 1359 / 639

On to step 4:
When dividing 1359 by 639, we get 2 with a remainder of 81.
Put 2 as the next digit of the answer. 
Result so far: 12.0
Subtract 1278 from 1359 to get 81.
Take the next digit (0) from the dividend and append it to 81, then repeat: 810 / 639

Advancing to step 5:
The number 639 fits into 810 1 times, leaving a remainder of 171.
Record the quotient 1 as the next digit in the result. 
Result so far: 121.0
Deduct 639 from 810 and we're left with 171.
Grab the next digit (3) from the dividend, add it to 171, then carry on: 1713 / 639

On to step 6:
639 can be fit into 1713 2 times, resulting in a remainder of 435.
Record the quotient 2 as the next digit in the result. 
Result so far: 1212.0
The remainder is 435 after subtracting 1278 from 1713.
Grab the next digit (2) from the dividend, add it to 435, then carry on: 4352 / 639

Moving on to step 7:
The number 639 fits into 4352 6 times, leaving a remainder of 518.
Write down 6 as next digit of the result. 
Result so far: 12126.0
The remainder is 518 after subtracting 3834 from 4352.
Grab the next digit (5) from the dividend, add it to 518, then carry on: 5185 / 639

Step 8:
5185 divided by 639 is 8 with a remainder of 73.
The number 8 becomes the next digit in our result. 
Result so far: 121268.0
If we subtract 5112 from 5185, we get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Step 9:
If we divide 730 by 639, we get 1 and a remainder of 91.
Write down 1 as next digit of the result. 
Result so far: 121268.1
Deduct 639 from 730 and we're left with 91.
Since there are no more digits in the dividend, we add a zero to the remainder making it 910, and continue the process.

Step 10:
When dividing 910 by 639, we get 1 with a remainder of 271.
The number 1 becomes the next digit in our result. 
Result so far: 121268.11
Subtract 639 from 910 to get 271.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2710, and continue the process.

In conclusion, the division gives 121268.11 with a balance of 0.271.