北师大版小学六年级数学简便运算练习题5页.docx

12.065.072.94 30.349.7610.34 33 2574 3441.7 1.250.8 1027.35.1 17+-7 1,a+b+c=a+ (b + c ), a+b-c=a +(b-c), a-b+c=a (b-c), a-b-c= a-( b +c);933-15.7-4.3 41.0619.7220.28 73+ 8+2-11+7+3abc=a(bc), abc=a(bc), abc=a(bc) , abc=a(bc),700145