We divide 66215164 by 400
We want to figure out the number of times 66215164 can be divided by 400.

Moving on to step 1:
400 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 400

Moving on to step 2:
400 can be fit into 66 0 times, resulting in a remainder of 66.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 66 leaves us with 66.
Include the next digit (2) from the dividend after 66, then repeat: 662 / 400

On to step 3:
400 goes into 662 1 times with a remainder of 262.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 400 from 662 to get 262.
Bring next digit (1) of the dividend behind the 262 and repeat the process: 2621 / 400

Advancing to step 4:
400 can be fit into 2621 6 times, resulting in a remainder of 221.
Write down 6 as next digit of the result. 
Result so far: 16.0
Deduct 2400 from 2621 and we're left with 221.
Append the next digit (5) from the dividend to 221 and continue with: 2215 / 400

On to step 5:
When dividing 2215 by 400, we get 5 with a remainder of 215.
Record the quotient 5 as the next digit in the result. 
Result so far: 165.0
If we subtract 2000 from 2215, we get 215.
Append the next digit (1) from the dividend to 215 and continue with: 2151 / 400

Let's proceed to step 6:
The number 400 fits into 2151 5 times, leaving a remainder of 151.
Record the quotient 5 as the next digit in the result. 
Result so far: 1655.0
Subtracting 2000 from 2151 leaves us with 151.
Include the next digit (6) from the dividend after 151, then repeat: 1516 / 400

Moving on to step 7:
400 can be fit into 1516 3 times, resulting in a remainder of 316.
Put 3 as the next digit of the answer. 
Result so far: 16553.0
If we subtract 1200 from 1516, we get 316.
Grab the next digit (4) from the dividend, add it to 316, then carry on: 3164 / 400

Let's proceed to step 8:
If we divide 3164 by 400, we get 7 and a remainder of 364.
Record the quotient 7 as the next digit in the result. 
Result so far: 165537.0
If we subtract 2800 from 3164, we get 364.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3640, and continue the process.

Advancing to step 9:
When dividing 3640 by 400, we get 9 with a remainder of 40.
Use 9 as the next digit of our solution. 
Result so far: 165537.9
Subtracting 3600 from 3640 leaves us 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.

Moving on to step 10:
400 divided by 400 is 1 with a remainder of 0.
Put 1 as the next digit of the answer. 
Result so far: 165537.91
If we take 400 away from 400, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 11:
400 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 165537.91
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 12:
0 divided by 400 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 165537.91
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 165537.91 with a remainder of 0.0.