x-x=10.8 +x=20×0.5 x:=2:1.75
x﹣1=0.2
x:=21:
50%x+x=15
8.9+3.01= 1- + = 1.2×5= 3.8÷0.038=
÷ = 3604÷62≈ 0.62-0.32= 1÷10%=
( - )×24= ×8÷ ×8=