45816105 ÷ 644 
Let's see how many times 644 fits into 45816105.

On to step 1:
If we divide 4 by 644, we get 0 and a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Include the next digit (5) from the dividend after 4, then repeat: 45 / 644

Advancing to step 2:
45 divided by 644 is 0 with a remainder of 45.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 45, we end up with 45.
Append the next digit (8) from the dividend to 45 and continue with: 458 / 644

Step 3:
644 goes into 458 0 times with a remainder of 458.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 458, we end up with 458.
Append the next digit (1) from the dividend to 458 and continue with: 4581 / 644

Let's proceed to step 4:
If we divide 4581 by 644, we get 7 and a remainder of 73.
Use 7 as the next digit of our solution. 
Result so far: 7.0
Subtract 4508 from 4581 to get 73.
Append the next digit (6) from the dividend to 73 and continue with: 736 / 644

Advancing to step 5:
The number 644 fits into 736 1 times, leaving a remainder of 92.
Record the quotient 1 as the next digit in the result. 
Result so far: 71.0
If we subtract 644 from 736, we get 92.
Bring next digit (1) of the dividend behind the 92 and repeat the process: 921 / 644

Moving on to step 6:
921 divided by 644 is 1 with a remainder of 277.
The number 1 becomes the next digit in our result. 
Result so far: 711.0
Deduct 644 from 921 and we're left with 277.
Include the next digit (0) from the dividend after 277, then repeat: 2770 / 644

Going ahead to step 7:
644 can be fit into 2770 4 times, resulting in a remainder of 194.
Put 4 as the next digit of the answer. 
Result so far: 7114.0
Deduct 2576 from 2770 and we're left with 194.
Include the next digit (5) from the dividend after 194, then repeat: 1945 / 644

Advancing to step 8:
When dividing 1945 by 644, we get 3 with a remainder of 13.
The next digit of our result is 3. 
Result so far: 71143.0
If we take 1932 away from 1945, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 9:
When dividing 130 by 644, we get 0 with a remainder of 130.
The number 0 becomes the next digit in our result. 
Result so far: 71143.0
Deduct 0 from 130 and we're left with 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1300, and continue the process.

Step 10:
When dividing 1300 by 644, we get 2 with a remainder of 12.
The next digit of our result is 2. 
Result so far: 71143.02
Subtract 1288 from 1300 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 11:
644 can be fit into 120 0 times, resulting in a remainder of 120.
The number 0 becomes the next digit in our result. 
Result so far: 71143.02
If we take 0 away from 120, we end up with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Advancing to step 12:
If we divide 1200 by 644, we get 1 and a remainder of 556.
Record the quotient 1 as the next digit in the result. 
Result so far: 71143.0201
If we subtract 644 from 1200, we get 556.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5560, and continue the process.

Step 13:
When dividing 5560 by 644, we get 8 with a remainder of 408.
The number 8 becomes the next digit in our result. 
Result so far: 71143.02018
Subtracting 5152 from 5560 leaves us with 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

On to step 14:
644 can be fit into 4080 6 times, resulting in a remainder of 216.
Put 6 as the next digit of the answer. 
Result so far: 71143.020186
Deduct 3864 from 4080 and we're left with 216.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2160, and continue the process.

Advancing to step 15:
644 can be fit into 2160 3 times, resulting in a remainder of 228.
Write down 3 as next digit of the result. 
Result so far: 71143.0201863
If we subtract 1932 from 2160, we get 228.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

On to step 16:
If we divide 2280 by 644, we get 3 and a remainder of 348.
Use 3 as the next digit of our solution. 
Result so far: 71143.02018633
If we subtract 1932 from 2280, we get 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

The final outcome is 71143.02018633, with a leftover of 3.48e-07.