考點(diǎn):小數(shù)四則混合運(yùn)算,運(yùn)算定律與簡便運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡算
分析:①首先計算括號內(nèi)的加法,然后計算減法;
②根據(jù)減法的性質(zhì),計算即可;
③根據(jù)加法結(jié)合律,計算即可;
④根據(jù)減法的性質(zhì),計算即可;
⑤⑥根據(jù)加法交換律和結(jié)合律,計算即可;
⑦5.96=6-0.04,然后根據(jù)減法的性質(zhì),計算即可;
⑧根據(jù)加法交換律和結(jié)合律,減法的性質(zhì),計算即可;
⑨首先計算括號內(nèi)的加法,然后計算減法;即可得解.
解答:
解:①55-(6.82+15.55)
=55-22.37
=32.63
②52-17.87-12.23
=52-(17.87+12.23)
=52-30.1
=21.9
③57+3.17+3.43+5.83
=(57+3.43)+(3.17+5.83)
=60.43+9
=69.43
④75-8.64-3.36
=75-(8.64+3.36)
=75-12
=63
⑤83-9.5-7.83-0.5
=83-7.83-(9.5+0.5)
=75.17-10
=65.17
⑥45+8.7+16.55+1.3
=45+16.55+(8.7+1.3)
=61.55+10
=71.55
⑦54-5.96
=54-(6-0.04)
=54-6+0.04
=48+0.04
=48.04
⑧38-5.34+2.62-4.66
=(38+2.62)-(5.34+4.66)
=40.62-10
=30.62
⑨63-(8.5+9.63)
=63-18.13
=44.87
點(diǎn)評:考查了運(yùn)算定律與簡便運(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)算律簡便計算.