Before weighing on a non-digital scale, you should:

• A. Zero the scale
• B. Check the weight by estimation
• C. Add a known weight and then zero it
• D. Weigh the patient directly without zeroing

Answer: (A)

Zeroing the scale is necessary to get an accurate reading. On a non-digital mechanical scale, there can be a small offset when the scale is empty due to prior use, residue, or an uneven surface. By adjusting the scale to read zero before placing the patient on it, you remove that offset so the measurement reflects only the patient’s weight. If you don’t zero first, the result will be skewed by the scale’s offset, leading to an inaccurate weight. Estimating the weight isn’t precise enough for CNA practice, adding a known weight isn’t part of how you weigh a patient, and weighing the patient without zeroing would produce an incorrect measurement.