+ = - = + = 1- =
- = + = - = + =
说理:__________。
0.25+0.5=
4.7-0.7=
1.2×5=
9÷0.3=
0.25a+0.5a=
7.8÷6=
1.2×0.5=
7-1.99=
62.4-4=
0.25a+0.05×2=
0.4+8.7= 4.5+3.6= 0.28+0.54= 1.4-0.9=
7.1-3.5= 5-2.7= 5.1-1.49= 15.3-4.8=
0.25