median
don steward
mathematics teaching 10 ~ 16

Thursday 30 June 2016

rearrangement add/take with letters

following on from a rearrangement of numerical statements (like, 14 + 8 = 22 so 14 = 22 - 8)

once some ideas of (and a language for) allowable transformations of statements has been fairly firmly established for arithmetic these same techniques can be used in rearrangement of symbolic statements (formulas or relationships)

for a sequence of rearrangement lessons,
a transition, or progression 
might start with simple number statements that can be easily checked;
then rearrange number statements with bigger numbers (less easy to check - but you still can, maybe with a calculator)
then to simple letter statements (e.g. h - d = k, so h = k + d)
to more complex (looking) symbolic statements

for example,
5 + 7 = 12 (e.g. to make 7 the subject, 7 = 12 - 5) and 9 - 4 = 5 to 9 = 5 + 4
to:  37 + 28 = 65   [37] and 46 - 29 = 17  [46]
to: a + c = b    [a]  and   m - t = k   [m]
to: a2b + c = fg3     [c]

a powerpoint is here






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