Correction du calcul mental:
9 x 10 = 90
9 x 20 = 180
9 x 30= 270
9 x 40 = 360
9 x 50 = 450
9 x 60 = 540
2 x 100 = 200
2 x 200= 400
2 x 300= 600
2 x 400 = 800
2 x 500 = 1000
3 x 100 = 300
3 x 200= 600
3 x 300= 900
3 x 400 = 1200
3 x 500 = 1500