We divide 42970357 by 21
We want to figure out the number of times 42970357 can be divided by 21.

Moving on to step 1:
When dividing 4 by 21, we get 0 with a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 21

Advancing to step 2:
The number 21 fits into 42 2 times, leaving a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Deduct 42 from 42 and we're left with 0.
Take the next digit (9) from the dividend and append it to 0, then repeat: 9 / 21

Going ahead to step 3:
The number 21 fits into 9 0 times, leaving a remainder of 9.
The next digit of our result is 0. 
Result so far: 20.0
Subtracting 0 from 9 leaves us with 9.
Bring next digit (7) of the dividend behind the 9 and repeat the process: 97 / 21

Let's proceed to step 4:
21 goes into 97 4 times with a remainder of 13.
Record the quotient 4 as the next digit in the result. 
Result so far: 204.0
Subtract 84 from 97 to get 13.
Append the next digit (0) from the dividend to 13 and continue with: 130 / 21

On to step 5:
When dividing 130 by 21, we get 6 with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 2046.0
If we subtract 126 from 130, we get 4.
Grab the next digit (3) from the dividend, add it to 4, then carry on: 43 / 21

Moving on to step 6:
If we divide 43 by 21, we get 2 and a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 20462.0
If we subtract 42 from 43, we get 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 21

Step 7:
15 divided by 21 is 0 with a remainder of 15.
Put 0 as the next digit of the answer. 
Result so far: 204620.0
Subtract 0 from 15 to get 15.
Bring next digit (7) of the dividend behind the 15 and repeat the process: 157 / 21

On to step 8:
157 divided by 21 is 7 with a remainder of 10.
Write down 7 as next digit of the result. 
Result so far: 2046207.0
If we subtract 147 from 157, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 9:
When dividing 100 by 21, we get 4 with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 2046207.4
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 10:
If we divide 160 by 21, we get 7 and a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 2046207.47
If we take 147 away from 160, 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.

Let's proceed to step 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 2046207.476
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 12:
When dividing 40 by 21, we get 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 2046207.4761
If we subtract 21 from 40, we get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 13:
21 goes into 190 9 times with a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 2046207.47619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 14:
When dividing 10 by 21, we get 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 2046207.47619
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 15:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 2046207.4761904
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 16:
If we divide 160 by 21, we get 7 and a remainder of 13.
The next digit of our result is 7. 
Result so far: 2046207.47619047
Subtract 147 from 160 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

In conclusion, the division gives 2046207.47619047 with a balance of 1.3e-08.