Direct Long Division 161
minus 16 is –16. We can’t work with –16, so the last digit of our
answer was too high.
32
–2
8
30 24.0
(We can easily see this, as 8 times 30 is exactly 240. We are not
dividing by 30, but by 32. Th e answer is correct for 30, but clearly
it is not correct for 32. Because each answer is only an estimate, we
can see in this case that we will have to drop our answer by 1.)
We change the answer to 7, so: 7 × 3 = 21, with 3 remainder.
Our calculation looks like this:
32
–2
7
30 24.^30
We now multiply:
7 × 2 = 14
Th en we subtract from 30:
30 – 14 = 16
Th e answer is 7 with 16 remainder.
If we want to take the answer to one decimal place, we now divide 16
by 3 for the next digit of the answer. Th ree divides into 16 fi ve times,
with 1 remainder. Th e 1 is carried to the next digit to make 10.
We multiply the last answer, 5, by the 2 in 32 to get an answer of
- Subtract 10 from our working number 10 to get an answer of 0.
Th ere is no remainder. Th e answer is exactly 7.5.