In the octal number system, the valid numbers are 0, 1, 2, 3, 4, 5, 6, 7. A subscript 8 indicates that a number is in octal format. For example, the octal number 23 appears as 23₈.

In general, an octal number is represented as:

a_n × 8ⁿ + a_n–1 × 8^n–1 + a_n–2 × 8^n–2 + ……… + a₀ × 8⁰

For example, octal number 237₈ can be shown as:

237₈ = 2 × 8² + 3 × 8¹ + 7 × 8⁰

Similarly, octal number 1777₈ can be shown as:

1777₈ = 1 × 8³ + 7 × 8² + 7 × 8¹ + 7 × 8⁰

In the hexadecimal number system, the valid numbers are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. A subscript 16 or subscript H indicates that a number is in hexadecimal format. For example, hexadecimal number 1F can be written as 1F₁₆ or as 1F_H. In general, a hexadecimal number is represented as:

a_n × 16ⁿ + a_n–1 × 16^n–1 + a_n–2 × 16^n–2 + ……… + a₀ × 16⁰

For example, hexadecimal number 2AC₁₆ can be shown as:

2AC₁₆ = 2 × 16² + 10 × 16¹ + 12 × 16⁰

Similarly, hexadecimal number 3FFE₁₆ can be shown as: