Figure 10.6 Super-zero
construction area to support his interest in parallel vertical lines. I must look out a
story about ladders, maybe one about fire engines.NNaammee::Joel Nash Date: 17 June Age: 7 years 2 months (see figure 10.6 above)
CCoonntteexxtt::whole class – mixed ages of 7 and 8 years. Joel has only been in our school
for a few weeks and is very anxious about having his representations of any sort,
including mathematics, judged as ‘wrong’. However, today he tackled the first
question and putting some of his working out on paper encouraged him to
experiment.
WWhhaatt tthhee cchhiilldd ssaaiidd::After he had worked out the answer to the first addition
question he reversed the calculation and compared the answers from both. When
he showed me he explained that he liked ‘doing sums both ways’ and that he was
going to do the same thing with a subtraction question. After working out ‘98 –15
= ‘ he wrote ‘15 –98 = ‘ and paused, looking puzzled. I asked him how he would
work this out. He looked around and, pointing to the number line on the table, said
that he would use this. Joel began by counting down from fifteen and then stopped
at nought. Moving his finger beyond the zero he said excitedly, ‘Super-zero! Zero,
zero, zero!’
WWhhaatt tthhee cchhiilldd ddiidd::Joel tried to reverse the subtraction calculation in the same way
that he had done with the addition sum. His idea of using the number line to count
down led him into the area of negative numbers.Developing children’s written methods 2038657part 2.qxd 04/07/2006 17:38 Page 203