资源描述
,*,中学生学习报,数学周刊,国家级优秀教辅读物,ISO9001,国际质量管理体系认证,人教课标七年级 上册,乘 方(,2,),人教版新课标七年级上册,1.,先乘方,再乘除,最后加减;,2.,同级运算,从左到右进行;,3.,如有括号,先做括号内的运算,按小括号,、,中括号,、,大括号依次进行,.,在做有理数混合运算时,应注意以下运算顺序,运算顺序,例,3,计算,(,2,),3,+(,3),(,4),2,+2,(,3),2,(,2),解:,原式,8+,(,3,),(,16+2,),9,(,2,),=,8+(,3),18,(,4.5),=,8,54+4.5=,57.5,总结例,3,运算的顺序?,例题解析,例,4,观察下面三行数:,2,,,4,,,8,,,16,,,32,,,64,,,0,,,6,,,6,,,18,,,30,,,66,,,1,,,2,,,4,,,8,,,16,,,32,,,(,1,)第,行数按什么规律排列,?,(,2,)第,行数与第第,行数分别有什么关系?,(,3,)取每行数的第,10,个数,计算这三个数的和,.,例题解析,解,(,1,)第,行数是,2,,,(,2),2,,,(,2),3,,,(,2),4,,,(,2,)对比,两行中位置对应的数,你有什么发现?第,行数是第,行相应的数加,2,,即,2+2,,(,2,),2,+2,,(,2,),3,+2,,(,2,),4,+2,,,2,,,4,,,8,,,16,,,32,,,64,,,0,,,6,,,6,,,18,,,30,,,66,,,1,,,2,,,4,,,8,,,16,,,32,,,对比,两行中位置对应的数,你有什么发现?第,行是第,行相应的数的,0.5,倍,即,2,0.5,,(,2,),2,0.5,,(,2,),3,0.5,,,(,2),4,0.5,,,(,3,)每行数中的第,10,个数的和是,(,2,),10,+,(,2,),10,+2,+,(,2,),10,0.5,1024+,(,1024+2,),+1024,0.5,1024+1026+512,2562,2,,,4,,,8,,,16,,,32,,,64,,,0,,,6,,,6,,,18,,,30,,,66,,,1,,,2,,,4,,,8,,,16,,,32,,,计算:,(,1,)(,1,),10,2+,(,2,),3,4,(,2,),思路:先算乘方,再算乘除,再算加减,解:原式,1,2+,(,8,),4,2+,(,2,),0,思路:先算乘方,再算乘法,再算减,练习,思路:先算括号内的运算,再从左到右,思路:注意算括号内的运算,解:原式,10000+,(,16,122,),10000,8,9992,(,4,)(,10,),4,+,(,4,),2,(,3+3,2,),2,(,3,),练习,有理数的混合运算法则,小结,1.,先乘方,再乘除,最后加减;,2.,同级运算,从左到右进行;,3.,如有括号,先做括号内的运算,按小括号,、,中括号,、,大括号依次进行,.,课后作业,47,页:,3,、,11,、,12,题,点拨,
展开阅读全文