987-567= 67+54=
536-32= 672+23=
10+34=
234+30=
410+14=
103+76=
67-24=
324-24=
560+14=
100-76=
87+7=
34-30=
678-75=
56+20=
21+18=
760-40=
640+60=
402-297≈
2100-900=
6000-1000=