8.1-2.7= 3.6×2.5= 2÷0.5= 0.81+0.3=
0.32= 7.8a-2.3a-0.7a= - = + =
45×20= 48+52= 0.48÷0.08= 1.25×8×0=
21÷3×7= 1+ = 9- - = + =
1- = 25×=15 6--=
=
× × 0.01