用简便方法计算.(1)42×98+42×2 (2)41×49-49&nbs
来源:学生作业帮 编辑:搜狗做题网作业帮 分类:数学作业 时间:2024/08/06 14:09:43
用简便方法计算.
(1)42×98+42×2
(2)41×49-49
(3)(4)5×34×4
(5)(125×12)×8
(6)700÷25÷4.72×102.
(1)42×98+42×2
(2)41×49-49
(3)(4)5×34×4
(5)(125×12)×8
(6)700÷25÷4.72×102.
![用简便方法计算.(1)42×98+42×2 (2)41×49-49&nbs](/uploads/image/z/3389448-48-8.jpg?t=%E7%94%A8%E7%AE%80%E4%BE%BF%E6%96%B9%E6%B3%95%E8%AE%A1%E7%AE%97%EF%BC%8E%EF%BC%881%EF%BC%8942%C3%9798%2B42%C3%972%26nbsp%3B%26nbsp%3B%26nbsp%3B%26nbsp%3B%EF%BC%882%EF%BC%8941%C3%9749-49%26nbs)
(1)42×98+42×2
=42×(98+2)
=42×100
=4200;
(2)41×49-49
=(41-1)×49
=40×49
=1960;
(3)5×34×4
=(5×4)×34
=20×34
=680;
(4)(125×12)×8
=125×8+12×8
=1000+96
=1096;
(5)700÷25÷4
=700÷(25×4)
=700÷100
=7;
(6)72×102
=72×100+72×2
=7200+144
=7344.
=42×(98+2)
=42×100
=4200;
(2)41×49-49
=(41-1)×49
=40×49
=1960;
(3)5×34×4
=(5×4)×34
=20×34
=680;
(4)(125×12)×8
=125×8+12×8
=1000+96
=1096;
(5)700÷25÷4
=700÷(25×4)
=700÷100
=7;
(6)72×102
=72×100+72×2
=7200+144
=7344.