10+8=
18
20-10=
10
10×2=
20
100:10=
20+5=
25
20-8=
12
20×2=
40
25÷5=
5
30+6=
36
30-9=
21
30×3=
90
30:5=
6
40+5=
45
40-20=
40×10=
400
40:10=
4
50+5=
55
50-20=
30
50×5=
250
50:10=