We're dividing 121551 by 76 
We want to figure out the number of times 121551 can be divided by 76.

On to step 1:
The number 76 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 76

Going ahead to step 2:
The number 76 fits into 12 0 times, leaving a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 12, we end up with 12.
Append the next digit (1) from the dividend to 12 and continue with: 121 / 76

Advancing to step 3:
76 can be fit into 121 1 times, resulting in a remainder of 45.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 76 from 121, we get 45.
Grab the next digit (5) from the dividend, add it to 45, then carry on: 455 / 76

Moving on to step 4:
76 goes into 455 5 times with a remainder of 75.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
Subtract 380 from 455 to get 75.
Append the next digit (5) from the dividend to 75 and continue with: 755 / 76

Let's proceed to step 5:
755 divided by 76 is 9 with a remainder of 71.
The next digit of our result is 9. 
Result so far: 159.0
If we take 684 away from 755, we end up with 71.
Take the next digit (1) from the dividend and append it to 71, then repeat: 711 / 76

Step 6:
76 goes into 711 9 times with a remainder of 27.
Use 9 as the next digit of our solution. 
Result so far: 1599.0
Deduct 684 from 711 and we're left with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

On to step 7:
If we divide 270 by 76, we get 3 and a remainder of 42.
Use 3 as the next digit of our solution. 
Result so far: 1599.3
If we take 228 away from 270, we end up with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

On to step 8:
The number 76 fits into 420 5 times, leaving a remainder of 40.
Record the quotient 5 as the next digit in the result. 
Result so far: 1599.35
Deduct 380 from 420 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 9:
The number 76 fits into 400 5 times, leaving a remainder of 20.
Write down 5 as next digit of the result. 
Result so far: 1599.355
The remainder is 20 after subtracting 380 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final result is 1599.355 with a remainder of 0.002.