简便计算; 1.9+1.99+1.999+1.9999+1.99999 28*1111+9999*8
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简便计算; 1.9+1.99+1.999+1.9999+1.99999 28*1111+9999*8
简便计算; 1.9+1.99+1.999+1.9999+1.99999 28*1111+9999*8
简便计算; 1.9+1.99+1.999+1.9999+1.99999 28*1111+9999*8
1.9+1.99+1.999+1.9999+1.99999
= 2-0.1 + 2-0.01 + 2- 0.001 +2- 0.0001 +2- 0.00001
= 10- 0.11111
= 9.88889
28*1111+9999*8
= 28*1111+ 1111*9*8
= 1111*(28+72)
= 1111*100
= 111100
1.9+1.99+1.999+1.9999+1.99999
= 2-0.1 + 2-0.01 + 2- 0.001 +2- 0.0001 +2- 0.00001
= 10- 0.11111
= 9.99999
28*1111+9999*8
= 28*1111+ 1111*9*8
= 1111*(28+72)
= 1111*100<...
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1.9+1.99+1.999+1.9999+1.99999
= 2-0.1 + 2-0.01 + 2- 0.001 +2- 0.0001 +2- 0.00001
= 10- 0.11111
= 9.99999
28*1111+9999*8
= 28*1111+ 1111*9*8
= 1111*(28+72)
= 1111*100
= 111100
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1.9+1.99+1.999+1.9999+1.99999
=2+2+2+2+2-0.1-0.01-0.001-0.0001-0.00001
=10-0.11111
=9.88889
28*1111+9999*8
=28÷9×1111×9+9999×8
=28/9×9999+9999×8
=（28/9+8）×9999
=100/9×9999
=111100
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