Read each number from top to bottom. Each digit is in base 20, and as I pointed out in another question of yours, 1 bar = 5, 1 dot = 1, and disk = 0.
(47) Only 1 digit here, with 2 bars and 4 dots. So this is 14.
(49) 3 digits, in order from top to bottom: 19, 0, 6. So this number is
[19]06₂₀ = 19×20² + 0×20¹ + 6×20⁰ = 7606
(51) 3 digits: 8, 8, 8.
888₂₀ = 8×20² + 8×20¹ + 8×20⁰ = 3368
(53) 4 digits: 2, 0, 0, 11.
200[11]₂₀ = 2×20³ + 0×20² + 0×20¹ + 11×20⁰ = 16011
(55) 4 digits: 10, 10, 0, 10.
[10][10]0[10]₂₀ = 10×20³ + 10×20² + 0×20¹ + 10×20⁰ = 84010
(57) 6 digits: 5, 10, 0, 6, 2, 3.
5[10]0623₂₀ = 5×20⁵ + 10×20⁴ + 0×20³ + 6×20² + 2×20¹ + 3×20⁰ = 17602443
(59) 6 digits: 10, 5, 0, 0, 11, 4.
[10]500[11]4₂₀ = 10×20⁵ + 5×20⁴ + 0×20³ + 0×20² + 11×20¹ + 4×20⁰ = 32800224
