- = + = + =
+ = - = - =
1- = + = - =
①171÷9+12
②13×15+200
③11×(27+43)
④(156﹣28)÷4
400÷80= 7.7+2.3= 4.2÷0.6= 1﹣0.91=
0.04×1000= 10÷1.25×9= 24×0.25= 23﹣1=
+= ×20=