Skill: Measure to a specified precision

First, identify:

1. What is being measured and its unit.
2. The required precision, such as the nearest centimetre or nearest tenth.
3. The scale reading, then round to the required place.

Example: A pencil is measured with a ruler. Its end is at $(12.7\text{ cm})$. Record its length to the nearest centimetre.

1. The unit is centimetres.
2. The required precision is the nearest centimetre, so the answer must be a whole number.
3. The pencil measures $(12.7\text{ cm})$. Look at the tenths digit, $7$.
4. Since $7$ is $5$ or more, round $(12)$ up to $(13)$.

Therefore, the pencil’s length to the nearest centimetre is

$$\boxed{13\text{ cm}}$$

Do not write $(12.70\text{ cm})$, because that gives more decimal places than the question asks for.