+=
-=
3-=
0.8+=
×18=
×=
3.2×=
、、、
+ = + = - = 0.5+ =
1- = 1- - = + + = + - + =
÷ = × ÷ × =
- = + - + =
÷0.4= + + = 1- + =
÷= ×= 1.02﹣0.43= 597×8≈
126÷3= 0.25×0.8= 1÷25%= 725÷92≈
阴影部分占,白色部分占。
86+124= ×63=49
2﹣= 1÷×=
10﹣3.6= 8.32÷4=
0.25×0.25= 0.38×90+3.8=