I’ll give you another way of dividing. One that is less well known and is interesting for dividing by multiple digits.
An example will make it clear:
Let’s say we need to know 100 / 21.
What we do is we divide by 20, easy peasy, and subtract a correction in the next step.
100 / 20 is 5. However, this leaves us with no remainder and in the next step we are going to subtract something, which takes us into negative territory. This is to be avoided, so we will use 4 instead of 5:
100 / 20 = 4 R 20
Now the correction: 4 R 20 - 4 X 1 = 4 R 16.
This is correct: 4 X 21 = 84 and 84 + 16 = 100.
We continue. the remainder of 16 becomes 160 and this fits 8 times into 20.
However; since we avoid negative remainders, we will use 7: 160 - 140 = 20.
So we have 47 R 20. Now the correction: 20 - 7x1 = 13.
Our answer so far: 47 R 13.
13 becomes 130 and this fits 6 times into 20: 130 - 120 = 10.
Answer: 476 R 10. correction: 6 X 1 = 6 and 10 - 6 = 4.
Answer: 476 R 4.
4 becomes 40 and this fits 2 times into 20.
Answer 4762 R 0. Correction: -2X1 = -2 so our answer is 4762 R -2.
Since our remainder is very small we can stop or use 4761 R 19 as the answer and continue from there.
Compare this to the previous post where we calculated 1/21.