题目内容
下面各题怎样算简便就怎样算 88.51-9.06-0.94 |
132+16.4+268+23.6 | 3.028-20.44+66.972 |
55.27+8.236-5.27 | 64.6-3.46+5.4-6.54 | 64.3-18.75+15.7-11.25. |
分析:(1)根据连续减去两个数等于减去这两个数的和简算;
(2)运用加法结合律简算;
(3)运用加法交换律简算;
(4)运用加法交换律简算;
(5)运用加法结合律简算以及连续减去两个数等于减去这两个数的和简算;
(6)运用加法结合律简算以及连续减去两个数等于减去这两个数的和简算.
(2)运用加法结合律简算;
(3)运用加法交换律简算;
(4)运用加法交换律简算;
(5)运用加法结合律简算以及连续减去两个数等于减去这两个数的和简算;
(6)运用加法结合律简算以及连续减去两个数等于减去这两个数的和简算.
解答:解:(1)88.51-9.06-0.94,
=88.51-(9.06+0.94),
=88.51-10,
=78.51;
(2)132+16.4+268+23.6,
=(132+268)+(16.4+23.6),
=400+40,
=440;
(3)3.028-20.44+66.972,
=(3.028+66.972)-20.44,
=70-20.44,
=49.56;
(4)55.27+8.236-5.27,
=(55.27-5.27)+8.236,
=50+8.236,
=52.236;
(5)64.6-3.46+5.4-6.54,
=(64.6+5.4)-(3.46+6.54),
=70-10,
=60;
(6)64.3-18.75+15.7-11.25,
=(64.3+15.7)-(18.75+11.25),
=80-30,
=50.
=88.51-(9.06+0.94),
=88.51-10,
=78.51;
(2)132+16.4+268+23.6,
=(132+268)+(16.4+23.6),
=400+40,
=440;
(3)3.028-20.44+66.972,
=(3.028+66.972)-20.44,
=70-20.44,
=49.56;
(4)55.27+8.236-5.27,
=(55.27-5.27)+8.236,
=50+8.236,
=52.236;
(5)64.6-3.46+5.4-6.54,
=(64.6+5.4)-(3.46+6.54),
=70-10,
=60;
(6)64.3-18.75+15.7-11.25,
=(64.3+15.7)-(18.75+11.25),
=80-30,
=50.
点评:此题是考查小数的加减混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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