Arrange the reasoning steps for deciding whether a measured quantity is a scalar or a vector.

### The order 1. **Identify the quantity being described.** You need to know what measurement you are classifying before judging its properties. 2. **Check whether the measurement includes magnitude.** Magnitude is the size or amount of the quantity. 3. **Decide whether a spatial direction is needed for a complete description.** Direction is the feature that separates vectors from scalars. 4. **Classify it.** A magnitude without direction is a scalar; magnitude with direction is a vector. ### The concept The test concerns whether direction matters to the quantity's complete description. A number alone is not enough to distinguish a scalar from a vector unless you know what the measurement represents. ### Terms - **Magnitude**: the size or amount of a quantity. - **Scalar**: a quantity with magnitude only. - **Vector**: a quantity with magnitude and direction. ### Remember Magnitude comes first; the need for direction decides scalar versus vector.