60< 13=9+ +=14
20> 15-=7 16=-
11-=7 15-=4 +2=11
-9=5 -8=7 7+=16
7+8=
15-7=
15-8=
7+= 16
16-=
12->12-
+7<7+
5549 16-711 17-816-8
1221 10+320 19-818-9