解:230减150等于( 80 )
∵已知需求出230减150等于多少
X - Y = Z
∴230减150
= 230 - 150
= (200 + 30)- (100 + 50)
= 200 + 30 - 100 - 50
= (200 - 100)+(30 - 50)
= 100 - 20
= 80
答:230减150等于80
解:230-150=230-(130+20)
=230-130-20
=100-20
=80
230-150
= 10x(23-15)
=10x8
=80