long division was not properly taught in the fourth grade may be due in
considerable measure to the fact that she has neglected at the beginning
of the fifth grade's work to spend a week or two in careful or
systematic review of the work covered in the previous year. The
complaint of high school teachers that children are not properly taught
in the elementary school would often be obviated if in each of the
fields in question some systematic review were given from time to time,
especially at the beginning of the work undertaken, in any particular
subject which involves work previously done in the elementary school.
During any year's work that teacher will be most successful who reviews
each day the work of the day before, who reviews each third or fourth
day the particularly difficult parts of the work done during the
previous periods, who reviews each week and each month, and even each
two or three months, the work which has been covered up to that time.
When teachers understand that the intervals between repetitions which
seem to have fixed a habit may only be gradually lengthened, then will
the formation of habits upon the part of boys and girls become more
certain, and the difficulties arising from lapses and inaccuracies
become less frequent.

As has been suggested in previous discussions, it will be necessary in
habit formation to vary the requirements among the individuals who
compose a group. The motive which we seek to utilize may make a greater
appeal to one child than to another. Physiological differences may
account for the fact that a small number of repetitions will serve to
fix the response for one individual as over against a very much larger
number of repetitions required for another. It is of the utmost
importance that all children work up to the maximum of their capacity.
It is very much better, for example, to excuse a boy entirely from a
given drill exercise than to have him dawdle or loaf during the period.