421786 ÷ 20 
We're looking to find how many times 20 goes into 421786.

Going ahead to step 1:
20 goes into 4 0 times with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 20

Advancing to step 2:
When dividing 42 by 20, we get 2 with a remainder of 2.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we subtract 40 from 42, we get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 20

Advancing to step 3:
The number 20 fits into 21 1 times, leaving a remainder of 1.
Put 1 as the next digit of the answer. 
Result so far: 21.0
If we subtract 20 from 21, we get 1.
Grab the next digit (7) from the dividend, add it to 1, then carry on: 17 / 20

Advancing to step 4:
20 goes into 17 0 times with a remainder of 17.
Write down 0 as next digit of the result. 
Result so far: 210.0
Subtract 0 from 17 to get 17.
Append the next digit (8) from the dividend to 17 and continue with: 178 / 20

Step 5:
If we divide 178 by 20, we get 8 and a remainder of 18.
Write down 8 as next digit of the result. 
Result so far: 2108.0
The remainder is 18 after subtracting 160 from 178.
Append the next digit (6) from the dividend to 18 and continue with: 186 / 20

Advancing to step 6:
The number 20 fits into 186 9 times, leaving a remainder of 6.
Use 9 as the next digit of our solution. 
Result so far: 21089.0
If we take 180 away from 186, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 7:
When dividing 60 by 20, we get 3 with a remainder of 0.
The number 3 becomes the next digit in our result. 
Result so far: 21089.3
If we subtract 60 from 60, we get 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 8:
If we divide 0 by 20, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 21089.3
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
If we divide 0 by 20, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 21089.3
If we take 0 away from 0, 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.

The final outcome is 21089.3, with a leftover of 0.0.