考點(diǎn):整數(shù)四則混合運(yùn)算
專(zhuān)題:運(yùn)算順序及法則
分析:(1)把原式3675-2998化為3675-3000+2來(lái)簡(jiǎn)化運(yùn)算.
(2)根據(jù)減去兩個(gè)數(shù)的和等于連續(xù)減去這兩個(gè)數(shù)求解.
(3)根據(jù)乘法分配律的逆運(yùn)算來(lái)簡(jiǎn)化運(yùn)算.
(4)根據(jù)乘法分配律的逆運(yùn)算來(lái)簡(jiǎn)化運(yùn)算,注意不要漏了1.
(5)把296化為300-4,簡(jiǎn)化運(yùn)算.
(6)把1001化為1000+1代入求解.
解答:
解:(1)3675-2998
=3675-3000+2
=675+2
=677
(2)2365-(307+365)
=2365-365-307
=2000-307
=1693
(3)(7×8715+3×8715)÷15
=(7+3)×8715÷15
=10×8715÷15
=87150÷15
=5810
(4)45×99+45
=45×(99+1)
=45×100
=4500
(5)563+296
=563+300-4
=863-4
=859
(6)1001×78
=(1000+1)×78
=1000×78+1×78
=78000+78
=78078
點(diǎn)評(píng):本題運(yùn)用減法的性質(zhì)、運(yùn)算律及拆分一個(gè)數(shù)來(lái)簡(jiǎn)算的問(wèn)題.