(Устно.)
10 * 2
10 * 5
10 * 3
10 * 6
20 * 2
20 * 3
20 * 4
20 * 5
30 * 2
30 * 3
40 * 2
50 * 2
10 * 2 = 20
10 * 5 = 50
10 * 3 = 30
10 * 6 = 60
20 * 2 = 40
20 * 3 = 60
20 * 4 = 80
20 * 5 = 100
30 * 2 = 60
30 * 3 = 90
40 * 2 = 80
50 * 2 = 100