23+4+9= 81﹣7﹣30= 54+20+3= 93﹣70+60=
17+6+8= 43﹣8﹣30= 60+38﹣90= 50+27﹣8=
68÷4= 840÷4= 220×4= 180÷3=
91÷7= 280÷2= 200×9= 0÷180=
23+4+9= 81﹣7﹣30= 54+20+3= 93﹣70+60=
17+6+8= 43﹣8﹣30= 60+38﹣90= 50+27﹣8=
68÷4= 840÷4= 220×4= 180÷3=
91÷7= 280÷2= 200×9= 0÷180=
+
+
=
﹣
=
+
﹣
=
+
﹣
=
+
= 7.5﹣（2.5+3.8）=
+
= 0.36+1.54= 135÷5= 2﹣
﹣
=
+
=
﹣
= 1﹣
﹣
=（
+
）﹣（
）=
﹣
=
+
+
﹣
﹣
+
﹣
+
﹣
+
+
﹣
．
+
= 1﹣
=
+
=
﹣
=
+
+
= 5÷8= 9.2×0.25×4= 0.8×25﹣10=
．
粤公网安备 44130202000953号