早教吧 育儿知识 作业答案 考试题库 百科 知识分享

用简便方法计算.355+260+140+245987-(287+135)89×99+891050÷15÷7.

题目详情
用简便方法计算.
355+260+140+245     
987-(287+135)
89×99+89            
1050÷15÷7.
▼优质解答
答案和解析
(1)355+260+140+245,
=(355+245)+(260+140),
=600+400,
=1000;

(2)987-(287+135),
=987-287-135,
=700-135,
=565;

(3)89×99+89,
=89×(99+1),
=89×100,
=8900;
    
(4)1050÷15÷7,
=1050÷(15×7),
=1050÷105,
=10.