CHRONO

-INF s.

Ajouter ou soustraire des dizaines entières.

CHRONO

0 s.
60 - 60 =
70 = 70 +
60 = 40 +
40 = 40 +
60 = 20 +
50 = 20 +
60 + 20 =
30 = 10 +
40 - 40 =
20 + 50 =
70 + 20 =
40 = 10 +
60 + 20 =
30 = 30 +
90 = 20 +
20 + 40 =
40 + 20 =
70 = 60 +
20 - 10 =
20 + 50 =