+=17 -=17
8-=6 9+=14 +3=11
6+=12 18-=10 8+=13
○○○
14
15
18
20
19
16
0.99+0.1= 0.35× = 0.75÷75%= 3.14×82=
2.7- = ÷8= 15×6÷15×6= ÷ ×0=