Question: A shelf measures 1216 mm long.
a) How many centimetres long is the shelf?
b) How many metres long is the shelf?
1. **State the problem:** We need to convert the length of a shelf from millimeters (mm) to centimeters (cm) and meters (m).
2. **Recall the conversion factors:**
- $1\text{ cm} = 10\text{ mm}$
- $1\text{ m} = 1000\text{ mm}$
3. **Convert millimeters to centimeters:**
$$1216\text{ mm} = \frac{1216}{10}\text{ cm}$$
4. **Simplify the fraction:**
$$= 121.6\text{ cm}$$
5. **Convert millimeters to meters:**
$$1216\text{ mm} = \frac{1216}{1000}\text{ m}$$
6. **Simplify the fraction:**
$$= 1.216\text{ m}$$
**Final answers:**
- a) The shelf is $121.6\text{ cm}$ long.
- b) The shelf is $1.216\text{ m}$ long.