(22)-(11)=11
(77)-(55)=22
(66)-(33)=33
(88)-(44)=44
减法公式
1、被减数-减数=差
2、差+减数=被减数
3、被减数-差=减数
减法相关性质
1、反交换率:减法是反交换的,如果a和b是任意两个数字,那么
(a-b)=-(b-a)
2、反结合律:减法是反结合的,当试图重新定义减法时,那么
a-b-c=a-(b+c)
(22)-(11)=11
(77)-(55)=22
(66)-(33)=33
(88)-(44)=44
共有六种:①22-11=11,66-44=22,77-33=44,88-55=33
②33-22=11,88-66=22,77-44=33,55-11=44
③22-11=11,77-55=22,66-33=33,88-44=44
④77-66=11,33-11=22,55-22=33,88-44=44
⑤88-77=11,44-22=22,66-33=33,55-11=44
⑥88-77=11,55-33=22,44-11=33,66-22