740 − 240 + 60 = 500 + 60 = 560
740 − (240 + 60) = 740 − 300 = 440
840 − 40 : 8 = 840 − 5 = 835
(840 − 40) : 8 = 800 : 8 = 100
66 − 6 * 9 + 1 = 66 − 54 + 1 = 12 + 1 = 13
(66 − 6) * 9 + 1 = 60 * 6 + 1 = 540 + 1 = 541
66 − 6 * (9 + 1) = 66 − 6 * 10 = 66 − 60 = 6
66 − (6 * 9 + 1) = 66 − (54 + 1) = 66 − 55 = 11
120 − 20 + 4 * 5 = 100 + 20 = 120
120 − (20 + 4) * 5 = 120 − 24 * 5 = 120 − 120 = 0
120 − (20 + 4 * 5) = 120 − (20 + 20) = 120 − 40 = 80
(120 − 20 + 4) * 5 = (100 + 4) * 5 = 104 * 5 = 520
500 : 100 * 5 = 5 * 5 = 25
500 : (100 * 5) = 500 : 500 = 1
300 : 10 : 10 = 30 : 10 = 3
300 : (10 : 10) = 300 : 1 = 300