Let's divide 9541721 by 420
We want to figure out the number of times 9541721 can be divided by 420.

On to step 1:
420 goes into 9 0 times with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Bring next digit (5) of the dividend behind the 9 and repeat the process: 95 / 420

Moving on to step 2:
If we divide 95 by 420, we get 0 and a remainder of 95.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 95 after subtracting 0 from 95.
Bring next digit (4) of the dividend behind the 95 and repeat the process: 954 / 420

Going ahead to step 3:
420 goes into 954 2 times with a remainder of 114.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtracting 840 from 954 leaves us with 114.
Append the next digit (1) from the dividend to 114 and continue with: 1141 / 420

Step 4:
420 goes into 1141 2 times with a remainder of 301.
The next digit of our result is 2. 
Result so far: 22.0
Deduct 840 from 1141 and we're left with 301.
Append the next digit (7) from the dividend to 301 and continue with: 3017 / 420

Moving on to step 5:
When dividing 3017 by 420, we get 7 with a remainder of 77.
Use 7 as the next digit of our solution. 
Result so far: 227.0
If we subtract 2940 from 3017, we get 77.
Bring next digit (2) of the dividend behind the 77 and repeat the process: 772 / 420

Let's proceed to step 6:
420 can be fit into 772 1 times, resulting in a remainder of 352.
Record the quotient 1 as the next digit in the result. 
Result so far: 2271.0
If we take 420 away from 772, we end up with 352.
Fetch the next digit (1) from the dividend, attach it to 352 and continue: 3521 / 420

On to step 7:
420 can be fit into 3521 8 times, resulting in a remainder of 161.
Use 8 as the next digit of our solution. 
Result so far: 22718.0
Deduct 3360 from 3521 and we're left with 161.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1610, and continue the process.

Advancing to step 8:
420 goes into 1610 3 times with a remainder of 350.
The number 3 becomes the next digit in our result. 
Result so far: 22718.3
Subtract 1260 from 1610 to get 350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3500, and continue the process.

Let's proceed to step 9:
420 goes into 3500 8 times with a remainder of 140.
Record the quotient 8 as the next digit in the result. 
Result so far: 22718.38
Deduct 3360 from 3500 and we're left with 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Step 10:
420 can be fit into 1400 3 times, resulting in a remainder of 140.
Put 3 as the next digit of the answer. 
Result so far: 22718.383
Subtracting 1260 from 1400 leaves us with 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Moving on to step 11:
When dividing 1400 by 420, we get 3 with a remainder of 140.
The next digit of our result is 3. 
Result so far: 22718.3833
If we subtract 1260 from 1400, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

The final outcome is 22718.3833, with a leftover of 0.0014.