For years I taught adding fractions the traditional way. I
taught it to the same pupils aged 11, I then taught it to them again aged 12.
Yes you’ve guessed it 13, 14 , 15 and 16. Colleagues I worked with did the
same, all with the same degree of success, or should I say failure, what is
wrong with these kids we would say they just don’t get it. After a long, long
time the ‘penny dropped’, it wasn’t them that didn’t get it, it was us Maths
teachers.
Last night I taught a 15 year old to add fraction together
in 15 minutes. She said ‘Is that it, it’s easy, for four years I was so
confused and now … wow.’ I then had to teach her mum to add two fractions
together who said why doesn’t everyone do that.
Most students can add two fractions together if the
denominator is the same, this fact is easy to establish. You then need to tell
them this is the only way to add two fractions if the bottom number is the same. Hopefully they agree. You then
present them with two fractions like those below.
Now highlight one of the denominators and say you will use
this to add the fractions. I find it really helpful to use colour, don’t
dismiss this simple trick if you want to be successful and more importantly if
you want the pupils to be successful.
Now highlight the other fraction.
Follow the same process. Multiply the other fraction by 3.
Finally complete the calculations like this
Point out the denominators are the same and then complete
the sum.
After a couple of examples the pupils will happily be adding
fractions. OK I know it isn’t perfect, such as when you have denominators of 2
and 4 but if you want them to be confident with adding fractions it is a really
brilliant method. You have to tech pupils to cancel down so the problem of
denominators of 2 and 4 is eventually tackled.
Will be using this method this eve when Molly asks if she has correctly answered her homework questions! Lisa
ReplyDeleteLet me know how successful it, I'm sure it will be. Steve
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