80421058 divided by 870 
We want to divide 80421058 by 870.

Advancing to step 1:
870 goes into 8 0 times with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 870

Moving on to step 2:
If we divide 80 by 870, we get 0 and a remainder of 80.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 80 and we're left with 80.
Include the next digit (4) from the dividend after 80, then repeat: 804 / 870

Going ahead to step 3:
When dividing 804 by 870, we get 0 with a remainder of 804.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 804, we end up with 804.
Take the next digit (2) from the dividend and append it to 804, then repeat: 8042 / 870

Advancing to step 4:
870 goes into 8042 9 times with a remainder of 212.
The next digit of our result is 9. 
Result so far: 9.0
The remainder is 212 after subtracting 7830 from 8042.
Bring next digit (1) of the dividend behind the 212 and repeat the process: 2121 / 870

On to step 5:
The number 870 fits into 2121 2 times, leaving a remainder of 381.
Write down 2 as next digit of the result. 
Result so far: 92.0
Deduct 1740 from 2121 and we're left with 381.
Include the next digit (0) from the dividend after 381, then repeat: 3810 / 870

Advancing to step 6:
The number 870 fits into 3810 4 times, leaving a remainder of 330.
The next digit of our result is 4. 
Result so far: 924.0
If we take 3480 away from 3810, we end up with 330.
Append the next digit (5) from the dividend to 330 and continue with: 3305 / 870

On to step 7:
870 goes into 3305 3 times with a remainder of 695.
Write down 3 as next digit of the result. 
Result so far: 9243.0
Subtract 2610 from 3305 to get 695.
Take the next digit (8) from the dividend and append it to 695, then repeat: 6958 / 870

Going ahead to step 8:
The number 870 fits into 6958 7 times, leaving a remainder of 868.
Write down 7 as next digit of the result. 
Result so far: 92437.0
Subtracting 6090 from 6958 leaves us with 868.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8680, and continue the process.

Going ahead to step 9:
When dividing 8680 by 870, we get 9 with a remainder of 850.
Use 9 as the next digit of our solution. 
Result so far: 92437.9
If we subtract 7830 from 8680, we get 850.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8500, and continue the process.

On to step 10:
The number 870 fits into 8500 9 times, leaving a remainder of 670.
Put 9 as the next digit of the answer. 
Result so far: 92437.99
Deduct 7830 from 8500 and we're left with 670.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6700, and continue the process.

After the division, we end up with 92437.99 and a remainder of 0.67.