如题所述
9.9+19.9+199.9+1999.9
= (10-0.1) + (20-0.1) + (200-0.1) + (2000-0.1)
= 10 + 20 +200 + 2000 - 0.4
= 2209.6
= (10-0.1) + (20-0.1) + (200-0.1) + (2000-0.1)
= 10 + 20 +200 + 2000 - 0.4
= 2209.6
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第1个回答 2010-06-22
9.9+19.9+199.9+1999.9
=(10-0.1)+(20-0.1)+(200-0.1)+(2000-0.1)
=2230-0.4
=2229.6
=(10-0.1)+(20-0.1)+(200-0.1)+(2000-0.1)
=2230-0.4
=2229.6
第2个回答 2010-06-22
9.9+19.9+199.9+1999.9
= (10-0.1) + (20-0.1) + (200-0.1) + (2000-0.1)
= 10 + 20 +200 + 2000 - 0.4
= 2230-0.4
=2229.6
= (10-0.1) + (20-0.1) + (200-0.1) + (2000-0.1)
= 10 + 20 +200 + 2000 - 0.4
= 2230-0.4
=2229.6
第3个回答 2010-06-22
9.9+19.9+199.9+1999.9 看成(10+20+200+2000)=2230
再用2230-(0.1*4)=2229.6
额..这样可以吗?
再用2230-(0.1*4)=2229.6
额..这样可以吗?
第4个回答 2010-06-22
9.9+19.9+199.9+1999.9=10+20+200+2000-0.4
=2229.6
=2229.6