解:(1)3060÷15-2.5×2.4,
=204-2.5×4×0.6,
=204-10×0.6,
=204-6,
=198;
(2)1.05×(3.8-0.8)÷6.3,
=1.05×3÷6.3,
=1.05×3÷(3×2.1),
=1.05×3÷3÷2.1,
=1.05÷2.1,
=0.5;
(3)2.1×4+1.6,
=8.4+1.6,
=10;
(4)5.25-(1.25+2.4),
=5.25-1.25-2.4,
=4-2.4,
=1.6;
(5)6.3×1.4+4.7×1.4-1.4,
=(6.3+4.7-1)×1.4,
=10×1.4,
=14;
(6)9÷2.5÷0.4,
=9÷(2.5×0.4),
=9÷1,
=9.
分析:(1)3060÷15-2.5×2.4,按運算順序計算即可;
(2)1.05×(3.8-0.8)÷6.3,把6.3拆成3×2.1與(3.8-0.8)=3進行簡算;
(3)2.1×4+1.6,按運算順序進行計算;
(4)5.25-(1.25+2.4),利用減法的性質(zhì),去括號以后,5.25和1.25結(jié)合進行簡算;
(4)6.3×1.4+4.7×1.4-1.4,應(yīng)用乘法分配律的逆運算簡算;
(5)9÷2.5÷0.4,利用除法的性質(zhì)簡算.
點評:此題考查學(xué)生小數(shù)四則混合運算的計算能力,在做此類計算時,如果能用簡便算法盡量用簡便算法.