4554 78-860+12 36+436-4
57-5057-5 32-2732-26 85-5080
40+30= 67+10= 38-8= 60+5=
80-50= 40-40= 63-50= 43-3=
39-30= 6+20= 92-12= 42+0=
70+5= 56-6= 84-80= 60+5=
59-51 △ 51+15 88-80 △ 99-90
34+54 △ 45+34 24+32 △ 28+30