The number that completes the sequence is 16.
The sequence seems to exhibit a clear pattern of alternating between doubling and halving each successive number. This regular alternation between operations suggests a systematic rule governing the sequence. Starting with the initial number, 8, the sequence doubles to 16, then halves to return to 8, doubles to 24, and halves again to 12. Continuing this pattern, the next logical step would be to double 12, resulting in 24. However, the actual number provided is 32. This deviation suggests the introduction of an additional factor, such as a constant increment or a different pattern, not solely based on doubling and halving.
While 16 was the next number in the sequence based on the established pattern, the unexpected inclusion of 32 raises the possibility of a more complex rule or an unforeseen element in the sequence. Without additional information or a clear rule, the sequence's exact nature remains somewhat ambiguous.