Convert $11011_2$ to base 10.

Expanding 11011₂: (1×2⁴) + (1×2³) + (0×2²) + (1×2¹) + (1×2⁰) = 16 + 8 + 0 + 2 + 1 = 27. Common errors include miscounting bit positions or omitting the zero-value term, leading to distractors like 25 or 31.