71391517 ÷ 450 
We want to divide 71391517 by 450.

Moving on to step 1:
450 goes into 7 0 times with a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Fetch the next digit (1) from the dividend, attach it to 7 and continue: 71 / 450

Step 2:
450 goes into 71 0 times with a remainder of 71.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 71 leaves us with 71.
Take the next digit (3) from the dividend and append it to 71, then repeat: 713 / 450

Moving on to step 3:
When dividing 713 by 450, we get 1 with a remainder of 263.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 450 from 713 leaves us with 263.
Grab the next digit (9) from the dividend, add it to 263, then carry on: 2639 / 450

Going ahead to step 4:
450 can be fit into 2639 5 times, resulting in a remainder of 389.
The next digit of our result is 5. 
Result so far: 15.0
If we subtract 2250 from 2639, we get 389.
Bring next digit (1) of the dividend behind the 389 and repeat the process: 3891 / 450

On to step 5:
When dividing 3891 by 450, we get 8 with a remainder of 291.
Use 8 as the next digit of our solution. 
Result so far: 158.0
Subtract 3600 from 3891 to get 291.
Append the next digit (5) from the dividend to 291 and continue with: 2915 / 450

Step 6:
The number 450 fits into 2915 6 times, leaving a remainder of 215.
The number 6 becomes the next digit in our result. 
Result so far: 1586.0
The remainder is 215 after subtracting 2700 from 2915.
Grab the next digit (1) from the dividend, add it to 215, then carry on: 2151 / 450

Moving on to step 7:
The number 450 fits into 2151 4 times, leaving a remainder of 351.
Record the quotient 4 as the next digit in the result. 
Result so far: 15864.0
Deduct 1800 from 2151 and we're left with 351.
Fetch the next digit (7) from the dividend, attach it to 351 and continue: 3517 / 450

Moving on to step 8:
450 goes into 3517 7 times with a remainder of 367.
Put 7 as the next digit of the answer. 
Result so far: 158647.0
The remainder is 367 after subtracting 3150 from 3517.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3670, and continue the process.

Going ahead to step 9:
When dividing 3670 by 450, we get 8 with a remainder of 70.
Put 8 as the next digit of the answer. 
Result so far: 158647.8
If we subtract 3600 from 3670, we get 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

On to step 10:
When dividing 700 by 450, we get 1 with a remainder of 250.
The number 1 becomes the next digit in our result. 
Result so far: 158647.81
The remainder is 250 after subtracting 450 from 700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

On to step 11:
If we divide 2500 by 450, we get 5 and a remainder of 250.
The number 5 becomes the next digit in our result. 
Result so far: 158647.815
If we subtract 2250 from 2500, we get 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

Going ahead to step 12:
450 can be fit into 2500 5 times, resulting in a remainder of 250.
The next digit of our result is 5. 
Result so far: 158647.8155
Subtract 2250 from 2500 to get 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

The final outcome is 158647.8155, with a leftover of 0.0025.