问题
解答题
简便计算
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答案
(1)722-301,
=700+22-(300+1),
=700-300+(22-1),
=400+21,
=421;
(2)235-190+165,
=(235+165)-190,
=400-(200-10),
=400-200+10,
=210;
(3)986-169-131,
=986-(169+131),
=986-300,
=686;
(4)167+141+359+33,
=(167+33)+(141+359),
=200+500,
=700;
(5)425+438+175,
=(425+175)+438,
=600+438,
=1038;
(6)463-148,
=440+23-(140+8),
=(440-140)+(23-8),
=300+15,
=315.