13. 10% of 40
= 40 × 0.10 = 4
14. 12% of 100
= 100 × .12 = 12
15. 99% of 60
= 60 × .99 = 59.4
16. 100% of 81
= 81 × 1 = 81
17. 45% of 360
= 360 × .45 = 162
18. 55% of 1,024
= 1024 × .55 = 563.2
19. 45 + n = 97
n = 97 - 45 = 52
20. n - 18 = 100
n = 100 + 18 = 118
21. n - 72 = 91
n = 91 + 72 = 163
22. n + 23 = 55
n = 55 - 23 = 32
23. 5 × t = 105
t = 105 ÷ 5 = 21
24. b ÷ 13 = 8
b = 8 × 13 = 104
25. k × 18 = 90
k = 90 ÷ 18 = 5
26. d ÷ 7 = 8
d = 8 × 7 = 56
