The Radius of a circular fan is 19.5 cm. What is the Diameter in dm

**Lesson Steps**:

1. Identify what we want - for us, we want the diameter

2. Identify what we have - for us, we have the radius

3. Find a useful equation - we know diameter = 2*radius

4. Calculate - 19.5cm * 2 = 39cm

5. Convert to the requested units - cm to dm needs a multiplication by 0.1

**Answer**:

We want the diameter and we have the radius. We know diameter = 2*radius. 19.5cm * 2 = 39cm

Finally, convert to the requested units. cm to dm needs a multiplication by 0.1. The answer is then 39cm * 0.1 dm/cm = 3.9dm

**Grade**: 7

**Level**: Junior high

**Subject**: Math

**Topic**: Word problem solving