+= ×= -= +=×9=
3×= 4-= ×= +2=-=
+ = - = - = + =
- = - = 1- = + =
+ = + = + = + =
- = - = - = 1- =
0.5×8= 3.6×0.4= 39.68×0= 7.6×1= 0.7×2.5×4=
4÷0.5= 12÷0.06= 12÷1.2= 3÷30= 7.5×1.2÷7.5×1.2=
143×7=1001
143×14=2002
143×21=3003
143×28=
……
143×=8008
×=38.5
×=3.85
385÷=0.385
①11+2x=12
②0.7x+3.6x=43
③7:x=:
④