500 - (91 - 91) : 7 - 6 * 2 = 488
1. 91 - 91 = 0
2. 0 : 7 = 0
3. 6 * 2 = 12
4. 500 - 0 = 500
5. 500 - 12 = 488
18 : 9 * 8 + (15 : 5 + 24) : 3 * 6 = 70
1. 15 : 5 = 3
2. 3 + 24 = 27
3. 18 : 9 = 2
4. 2 * 8 = 16
5. 27 : 3 = 9
6. 9 * 6 = 54
7. 16 + 54 = 70