750 + 250 =
300 + 700 =
100 - 90=
500 - 490 =
950 + 50=
20 + 20 +20 +20 +20 =
10 + 80 + 10=
600 - 300 -200 =
20 - 7 - 3 =
70 + 30 =
70 - 60=
900 -800 =
4 + 6=
400 + 600 =
475 - 300 - 75=
75 - 60 - 5 =
50 +50 =
15 - 5=
400 - 200 -100=
800 + 100 +100=
520 - 420 =
500 + 500 =
80 + 20 =