Convert 3.5 litres into millilitres.

Appeared in: RML MAINS 2025

Explanation

The fundamental conversion factor in the metric system is that 1 litre (L) is equal to 1000 millilitres (mL).
To convert from a larger unit (litres) to a smaller unit (millilitres), you need to multiply.
The correct calculation is multiplying the given volume in litres by 1000: 3.5 L × 1000 = 3500 mL.

Option A: This value, 300 ml, is equivalent to 0.3 L. It represents a miscalculation and does not correspond to 3.5 L.
Option B: This value, 350 ml, is the result of incorrectly multiplying by 100 instead of 1000. This is a common decimal error.
Option D: This value, 35 ml, is the result of incorrectly multiplying by 10 instead of 1000. This represents a significant miscalculation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Unit conversion: Litres to Millilitres as background academic context rather than a clinical decision trigger.
Accurate fluid calculation is a critical nursing skill for medication administration, IV fluid management, and monitoring patient intake/output to prevent dehydration or fluid overload.
Dosage errors, often stemming from simple mathematical mistakes like decimal point placement or using the wrong conversion factor, are a major patient safety risk.
In clinical practice, a leading zero should always be used before a decimal (e.g., 0.5 mL), but a trailing zero should be avoided (e.g., use 5 mL, not 5.0 mL) to prevent tenfold overdose errors if the decimal is missed.

How to Approach the Question

Identify the core task: The question asks for a unit conversion from a larger unit (litres) to a smaller unit (millilitres).
Recall the key conversion factor: Remember that the prefix 'milli' means one-thousandth, so 1 litre = 1000 millilitres.
Determine the mathematical operation: When converting from a larger unit to a smaller unit, you multiply.
Set up and perform the calculation: Multiply the given litre value by the conversion factor: 3.5 × 1000.
Solve the equation: 3.5 × 1000 = 3500.
Match the result to the options provided and select the corresponding answer.

Concept Tested & Keywords

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E6 Nursing Fundamentals Taylor p. 848-850

E6 Nursing Fundamentals Potter Perry 12e Part 3 p. 141-143

E6 Nursing Vital Signs p. 115-117

Practise the full RML MAINS 2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.