7643 Octal in Decimal

Let's convert the octal number 7643 to decimal without using a calculator:

Write down the powers of 8 starting from the right, with the first digit corresponding to 8⁰, the second to 8¹, the third to 8², and so on.

Convert each octal digit to its decimal equivalent:

78 = 710

68 = 610

48 = 410

38 = 310

Multiply each octal digit by its corresponding power of 8 and sum the results.

(7 × 512) + (6 × 64) + (4 × 8) + (3 × 1) = 3584 + 384 + 32 + 3 = 4003