考點(diǎn):小數(shù)四則混合運(yùn)算,整數(shù)四則混合運(yùn)算
專(zhuān)題:運(yùn)算順序及法則
分析:(1)根據(jù)加法交換律和結(jié)合律進(jìn)行簡(jiǎn)算;
(2)根據(jù)減法的性質(zhì)進(jìn)行簡(jiǎn)算;
(3)先算除法,再算加法,最后算乘法;
(4)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(5)24=8×3,然后再根據(jù)乘法結(jié)合律進(jìn)行簡(jiǎn)算;
(6)先算除法,再算乘法,最后算加法;
(7)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(8)根據(jù)除法的性質(zhì)進(jìn)行簡(jiǎn)算;
(9)202=200+2,然后再根據(jù)乘法分配律進(jìn)行簡(jiǎn)算.
解答:
解:(1)54.8+23+15.2+77
=(54.8+15.2)+(23+77)
=70+100
=170;
(2)43.5-6.5-13.5
=43.5-(6.5+13.5)
=43.5-20
=23.5;
(3)(300+750÷15)×8
=(300+50)×8
=350×8
=2800;
(4)84×15+116×15
=(84+116)×15
=200×15
=3000;
(5)125×24
=125×(8×3)
=(125×8)×3
=1000×3
=3000;
(6)184+240÷8×16
=184+30×16
=184+480
=664;
(7)(25+45)×4
=25×4+45×4
=100+180
=280;
(8)1240÷25÷4
=1240÷(25×4)
=1240÷100
=12.4;
(9)202×48
=(200+2)×48
=200×48+2×48
=9600+96
=9696.
點(diǎn)評(píng):考查了運(yùn)算定律與簡(jiǎn)便運(yùn)算,四則混合運(yùn)算.注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算定律簡(jiǎn)便計(jì)算.