RussellMc wrote:
> On 17 January 2014 10:11, Rossano Gobbi <rossano86@hotmail.com> wrote:
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>> Maybe useful if you are teaching to someone who can't understand the
>> classic way.
>>
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> Probably.
> And/but there are other similar ways of doing the same thing.
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> Below "[" and "]" are unnecessary and used for 'clarity'.
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> eg
> 63 x 27
> =3D (60 + 3) x (20 + 7)
> =3D [60 x 20] + [3 x 20] + [7 x 60] + [3 x 7]
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> =3D 100 x [6 x 2] + [3 x [2 x 10] ] + [7 x [6 x 10]] + [3 x 7]
> The 'complicated' adding a 0 to 6 to make it 60 then separating it again
> coud be omitted but has some explanatory power.
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> =3D 12 x 100   + 6 x 10 + 42 x 10  + 21    <Add [] as desired>
> =3D 1200  +(6 + 42) x 10  + 21
> =3D 1200 + 480 + 21
> =3D 1701
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> Obviously this could be 'much shortened' but still be more expanded than
> usual and help with understanding.
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> _______________________
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> even
> 63 x 27
> =3D 1200 + 60 + 420 + 21
> =3D 1701
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> Can be 'rapidly enough arrived at once the positional depiction of powers
> of 10 is understood.
> ie 63 =3D 60+3
> 27 =3D 20  +7.
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> R
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>>> What's the name of this strange method?
>>>> How does it work?
>>>>
>> https://www.facebook.com/photo.php?v=3D1378789205699173&set=3Dvb.1374352=
292809531&type=3D2&theater
>>> It's a graphical way of showing the actions that you would do when
>>> performing the same calculation by other means.
>>> It gets messy when you get larger digits involved.

--=20
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