小学奥数题简便计算

98÷2×151 7／5×64+2／7×65 (0.625+0.385)÷(0.1-0.09)

第1个回答 2014-04-24

98÷2×151
=49/2*151
=24.5*150+24.5
=3675+24.5
=3699.5

7／5×64+2／7×65
=7/5*65+2/7*65-7/5
=（7/5+2/7）*65-7/5
=59/35*65-7/5
=767/7-7/5
=760/7

(0.625+0.385)÷(0.1-0.09)
=（0.625+0.385）*100
=0.625*100=0.385*100
=62.5+38.5
=101

第2个回答 2014-04-24

原式=49*151=（50-1）*151=50*151-1*151=7550-151=7399

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