脱式计算.(能简便计算的要简便计算)55×202 35×115-35×15 864÷[(38-34)×12] 1200÷125.
第1个回答 2014-12-09
(1)55×202
=55×200+55×2
=11000+110
=11110;
(2)35×115-35×15
=35×(115-15)
=35×100
=3500;
(3)864÷[(38-34)×12]
=864÷[4×12]
=864÷48
=18;
(4)1200÷125
=(1200×8)÷(125×8)
=9600÷1000
=9.6.
=55×200+55×2
=11000+110
=11110;
(2)35×115-35×15
=35×(115-15)
=35×100
=3500;
(3)864÷[(38-34)×12]
=864÷[4×12]
=864÷48
=18;
(4)1200÷125
=(1200×8)÷(125×8)
=9600÷1000
=9.6.