4 O 9 O 6 = 6
13 O 5 O 5 = 60
42 O 6 O 4 = 28
3 O 17 O 4 = 55
4 * 9 : 6 = 6
13 * 5 − 5 = 60
42 : 6 * 4 = 28
3 * 17 + 4 = 55
Проверка:
$4 \overset{1}{*} 9 \overset{2}{:} 6 = 6$
1) 4 * 9 = 36
2) 36 : 6 = 6
$13 \overset{1}{*} 5 \overset{2}{-} 5 = 60$
1) 13 * 5 = (10 + 3) * 5 = 50 + 15 = 65
2) 65 − 5 = 60
$42 \overset{1}{:} 6 \overset{2}{*} 4 = 28$
1) 42 : 6 = 7
2) 7 * 4 = 28
$3 \overset{1}{*} 17 \overset{2}{+} 4 = 55$
1) 3 * 17 = 3 * (10 + 7) = 3 * 10 + 3 * 7 = 30 + 21 = 51
2) 51 + 4 = 55