+ = - = + = 1- =
- = +2= -0= -1=
= = =
+ = 4× = - = ÷ = × =
2- = ÷ = × = ×0= ÷ =
+ = - = + = 0.5+ = 83=
- = +2= 1- = -0.75= 122=
+ = + = - = 0.5+ =
1- = 1- - = + + = + - + =
0.32= 2.8×0.3= 1-= 1.4+0.16=
2.5-1.3= 9÷5= 2.5×4÷2.5×4= 2.8+7.2×0=
口答:需要放在( )个笔筒里。
口答:5个笔筒里有( )支笔。