350 － 50 =
740 － 30 =
900 － 400 =
20 ＋ 700 =
200 ＋ 40 =
10 ＋ 100 =
80 ＋ 500 =
300 ＋ 700 =
450 － 400 =
420 － 10 =
350 － 50 =
740 － 30 =
900 － 400 =
20 ＋ 700 =
200 ＋ 40 =
10 ＋ 100 =
80 ＋ 500 =
300 ＋ 700 =
450 － 400 =
420 － 10 =