13–8 = 17–3 =22+5 =60+23 –3=
43+ 20=7+60=68– 6=88– 50+30 =
88–7 = 6+9 =13-9=75–60+70=
90–20= 50+48 = 74–40 =78–8–30 =
49+ 40=15–8= 30+60 =32+50–40 =