小学数学简便运算题1-2/3-2/9-2/27-2/81-2/243-2/7293/4+3/28+3/70+3/130+3/208 2005+2006×2004 ———————— 2005×2006-1
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![小学数学简便运算题1-2/3-2/9-2/27-2/81-2/243-2/7293/4+3/28+3/70+3/130+3/208 2005+2006×2004 ———————— 2005×2006-1](/uploads/image/z/54581-5-1.jpg?t=%E5%B0%8F%E5%AD%A6%E6%95%B0%E5%AD%A6%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97%E9%A2%981-2%2F3-2%2F9-2%2F27-2%2F81-2%2F243-2%2F7293%2F4%2B3%2F28%2B3%2F70%2B3%2F130%2B3%2F208++2005%2B2006%C3%972004++%E2%80%94%E2%80%94%E2%80%94%E2%80%94%E2%80%94%E2%80%94%E2%80%94%E2%80%94++2005%C3%972006-1)
小学数学简便运算题1-2/3-2/9-2/27-2/81-2/243-2/7293/4+3/28+3/70+3/130+3/208 2005+2006×2004 ———————— 2005×2006-1
小学数学简便运算题
1-2/3-2/9-2/27-2/81-2/243-2/729
3/4+3/28+3/70+3/130+3/208
2005+2006×2004
————————
2005×2006-1
小学数学简便运算题1-2/3-2/9-2/27-2/81-2/243-2/7293/4+3/28+3/70+3/130+3/208 2005+2006×2004 ———————— 2005×2006-1
【1】.1-2/3-2/9-2/27-2/81-2/243-2/729
=1/3-2/9-2/27-2/81-2/243-2/729
=1/9-2/27-2/81-2/243-2/729
=····
=1/729
【2.】3/4+3/28+3/70+3/130+3/208
=(1-1/4)+(1/4-1/7)+(1/7-1/10)+(1/101/13)+(1/13-1/16)
=1- 1/16
=15/16
【3.】 2005+2006×2004
————————
2005×2006-1
2005+(2005+1)(2005-1)
=------------------------
2005×(2005+1)-1
2005+2005*2005-1
=------------------
2005*2005+2005-1
2005*2005+2004
=---------------
2005*2005+2004
=1