70-3030 7869 80-1070-30
+8=11 4+=13
12-=7 +=16
11-=9 5+=14
9+6=+8 11-3=-5
99 29 54 83 9 87
<<<<<
+8=41 13-=6 -9=74 30+=30-
18->10 +60<67 -8>14 50-=42+
16-9=
5+6=
7+8=
12-4=
14-6=
7+23=
21-7=
36-8=
50-35=
64-34=
24.06+0.4= += 5﹣+= 2.5×44=
15÷1%= 2.4×= 4×÷4×= 30÷62.5%=