题目内容
脱式计算
(27+53)×7 | 560+56×2 | 28×(46-37) |
21+13×3 | 354-78+122 | 16×7×9. |
分析:(1)先算小括号里面的加法,再算括号外的乘法;
(2)先算乘法,再算加法;
(3)先算小括号里面的减法,再算括号外的乘法;
(4)先算乘法,再算加法;
(5)(6)按照从左到右的顺序计算.
(2)先算乘法,再算加法;
(3)先算小括号里面的减法,再算括号外的乘法;
(4)先算乘法,再算加法;
(5)(6)按照从左到右的顺序计算.
解答:解:(1)(27+53)×7,
=80×7,
=560;
(2)560+56×2,
=560+112,
=672;
(3)28×(46-37),
=28×9,
=252;
(4)21+13×3,
=21+39,
=60;
(5)354-78+122,
=276+122,
=398;
(6)16×7×9,
=112×9,
=1008.
=80×7,
=560;
(2)560+56×2,
=560+112,
=672;
(3)28×(46-37),
=28×9,
=252;
(4)21+13×3,
=21+39,
=60;
(5)354-78+122,
=276+122,
=398;
(6)16×7×9,
=112×9,
=1008.
点评:1.一个算式里,如果含有两级运算,要先做第二级运算,后做第一级运算.
2.一个算式里,如果有括号,要先算小括号里的,再算括号外的.
2.一个算式里,如果有括号,要先算小括号里的,再算括号外的.
练习册系列答案
相关题目