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Crib Sheet Our daily guide to educational jargon,
teaching methods and the strange things children may bring back
from school as homework. If there is a particular aspect of your
child's education you wish explaining, use the POL Ask
an Expert service. Commutativity in Maths This isn't a word your child is likely to hear during maths lessons, but it's still an important concept. It quite simply means that you can carry out maths operations (such as adding, subtracting, multiplying and dividing) either way round and still get the same result. Adding and multiplying are commutative. The answer to the sum 3+8 is 11. So is the answer to the sum 8+3. Similarly, 8 X 3 = 24 -- and so does 3 X 8. However, if you consider the sum 15-8=7 it is clear that you get a different answer than you would if you took fifteen from eight (8-15). Division works the same way - 6 divided by 3 gives a different answer than 3 divided by 6. Although this probably seems perfectly straightforward, quite a number of children find it difficult to grasp, and a lack of understanding can lead to hard-to-spot errors in their number work. |