Posted by Peter on 18th April 2012

# More long division: 3-digits divided by 2-digits

One of the hardest things children try to do in primary school is long division. It is hard because it requires a good knowledge of tables,  the ability to multiply, estimate, use trial and improvement and go through several steps to reach the answer. These steps include:

e.g. 789 divided by 36

First carry out an estimate of the answer. I think 789 divided by 36 is about 20.

a. How many 36s in 78?

b. 2 x 36 is 72.    3 x 36 is 108 which is too many, so it must be 2.

c. Put the 2 in the tens column above the question.

d. Place the 72 below the 78 and subtract.

e. 78 – 72 is 6.

f. ‘Bring down’ the 9 to make 69.

g. How many 36s in 69.

h. By trial and improvement and some rough work multiplying 36 by my estimated numbers I find that 36 x 1 = 36.

i. Put the 1 in the units column above the question.

j. Place the 36 under the 69 and subtract.

k. The remainder (33) must be less than the original number you are dividing by.

Good luck with these, but many year 6 children will find them too tricky! When I was at school I used to like doing pages of these because I had learnt the method ‘off by heart’ and it was just a matter of repeating it.

Division 3 by 2