18 - 1=
4 + 5 =
9 – 7 =
6 + 7=
5 + 9 =
7 + 8 =
9 + 1=
12 + 5=
8 + 4=
3 + 12=
14 - 2=
13
14
17
15
12
10
19 – 8 =
11
20+30=
90-50=
60+40=
20-20=
30+50=
100-30=
50
40
100
80
70
