+-=+-=-+=
10+30> 20+<25
35+<40 46->40
+52<60 54-50>
5969 4994 17-89 7+919-3
5+820-4 13-75+4 13-87 15+319-3
- = × = 80÷10%= 42×3.14=
30%+0.45= 3.6÷0.18= 2- = 6- - =
5.2÷0.04= 1.32+0.8= 8 ÷8= 25+7.5=
51.51÷51= + ÷ = 1.5×2÷1.5×2= 149÷30≈