90-9=
98-70=
65+20=
86-5=
4+65=
20+67=
73-40=
85-7=
76-60=
24-10=
23+4= 8+16= 60-40= 12+20=
36-10= 36+40= 48-8= 36-16=
45+8= 72-2= 34+50= 73-20=
28+12=
42-9=
4×2=
2×6+3=
15+30=
39-20=
3×5=
5×5-20=
18个
12个
19个