2451121 divided by 644 
Let's see how many times 644 fits into 2451121.

Step 1:
The number 644 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Fetch the next digit (4) from the dividend, attach it to 2 and continue: 24 / 644

On to step 2:
644 can be fit into 24 0 times, resulting in a remainder of 24.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 24 after subtracting 0 from 24.
Grab the next digit (5) from the dividend, add it to 24, then carry on: 245 / 644

Let's proceed to step 3:
644 goes into 245 0 times with a remainder of 245.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 245 after subtracting 0 from 245.
Append the next digit (1) from the dividend to 245 and continue with: 2451 / 644

Let's proceed to step 4:
When dividing 2451 by 644, we get 3 with a remainder of 519.
The next digit of our result is 3. 
Result so far: 3.0
If we subtract 1932 from 2451, we get 519.
Include the next digit (1) from the dividend after 519, then repeat: 5191 / 644

On to step 5:
644 can be fit into 5191 8 times, resulting in a remainder of 39.
Put 8 as the next digit of the answer. 
Result so far: 38.0
If we subtract 5152 from 5191, we get 39.
Include the next digit (2) from the dividend after 39, then repeat: 392 / 644

Moving on to step 6:
644 goes into 392 0 times with a remainder of 392.
The next digit of our result is 0. 
Result so far: 380.0
If we subtract 0 from 392, we get 392.
Take the next digit (1) from the dividend and append it to 392, then repeat: 3921 / 644

Let's proceed to step 7:
3921 divided by 644 is 6 with a remainder of 57.
Put 6 as the next digit of the answer. 
Result so far: 3806.0
If we take 3864 away from 3921, we end up with 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Let's proceed to step 8:
644 can be fit into 570 0 times, resulting in a remainder of 570.
Write down 0 as next digit of the result. 
Result so far: 3806.0
Deduct 0 from 570 and we're left with 570.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5700, and continue the process.

Advancing to step 9:
644 goes into 5700 8 times with a remainder of 548.
The next digit of our result is 8. 
Result so far: 3806.08
If we take 5152 away from 5700, we end up with 548.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5480, and continue the process.

Going ahead to step 10:
If we divide 5480 by 644, we get 8 and a remainder of 328.
Use 8 as the next digit of our solution. 
Result so far: 3806.088
The remainder is 328 after subtracting 5152 from 5480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3280, and continue the process.

The quotient of the division is 3806.088, and the remainder is 0.0328.