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Matrix method of multiplication. Multiply decimals without confusion by firstly converting to integers e.g. 0.0123 x 0.456 = 123 x 10 -4 x 456 x 10 -3 = 123 x 456 x 10 -7 Use matrix method to find 123 x 456 = 56,088 Answer is therefore 56,088 x 10 -7 = 0.0056088 - PowerPoint PPT Presentation
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Mathematics topic handout: Long multiplication Dr Andrew French. www.eclecticon.info PAGE 1
123 x 456 = =
40,000800012005000100015060012018---------56,088
1815012003
1201000800020
6005000000,40100
650400Multiply decimals without confusion by firstly converting to integers
e.g. 0.0123 x 0.456
= 123 x 10-4 x 456 x 10-3
= 123 x 456 x 10-7
Use matrix method to find 123 x 456 = 56,088
Answer is therefore 56,088 x 10-7 = 0.0056088
Or just take care with the decimal point and use the matrix method as before
Matrix method of multiplication
23
21
2
2
21 22
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x
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x
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252
21
2
4222
2
212 222
2
yyxxyx
yx
yyxyy
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yx
yxyx
6116
622
933
3
3
323)3(21 232
2322
xxx
x
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0.15 x 17.2 = =
1.000.700.020.500.350.01---------2.58
01.035.05.005.0
02.07.011.0
2.0710
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