參考答案
(1)26×25×4(2)125×19×8(3)125×25×32
=26×100 =125×8×19 =125×8×25×4
=2600 =1000×19 =1000×100
=19000 =100000
(4)(100-4)×25(5)351×99(6)261×11
=100×25-4×25 =351×(100-1) =261×(10+1)
=2500-100 =351×100-351 =261×10+261
=2400 =35100-351 =2610+261
=34749 =2871
(7)34×27+66×27 (8)143×38-43×38
=(34+66)×27 =(143-43)×38
=100×27 =100×38
=2700 =3800
(9)999×778+333×666(10)28×5+2×4×35+21×20
=999×778+999×222 =140+2×140+3×140
=999×(778+222) =140×(1+2+3)
=999000 =840
(11)2013×20142014÷2014×20132013=
=2013×2014×10001÷2014×2013×10001
=1
(12)456456+654654
=456×1001+654×1001=(456+654)×1001=1110×1001=1111110