In this lesson, students will practice measuring lengths by measuring different things with non-standard measuring tools.

This lesson begins with a discussion on measurement, followed by a demonstration to highlight potential errors students may encounter, and then students will practice measuring.

**Discussion:**

To engage students, and help guide them towards understanding the importance of precise measurement, begin by asking students to think about why they might want to measure something. “Why would it be useful to measure your foot? A piece of wood? The size of a doorway?”

Next, ask students to brainstorm what objects they might use to measure lengths. We will look at standard units in the next lesson. For this lesson, steer students towards non-standard measuring devices. For example, you could measure your forearm with a bottle cap, or the doorway with your shoe. Ask students to predict what might make for a good measuring tool, and what would be difficult to measure with.

**Demonstration:**

Use a non-standard measuring tool to demonstrate how students will measure. You can continue with the previous example, and measure your arm with a bottle cap. Move it along your arm, counting how many lengths of the bottle cap you need. You could also measure a doorway with your shoe.

Note common errors for students to avoid such as:

- Beware extra space. When moving your measuring tool, make sure it is lined up with no extra space. Using a pencil mark, or piece of tap can help with this. Beware, if you use a friend’s finger, that finger will take up space you should be measuring.
- Beware if you are using multiple of the same measuring tool, the second should be touching the first. For example, if you are using your shoes, the heel of the second should be touching the toe of the first.
- Beware curving lines, and edges. Start from one edge of what your are measuring, and move in a straight line to the opposite edge.

**Activity: Student practice**

Encourage students to choose a varied selection of non-standard measuring tools, and a varied selection of objects to measure.

Show students how your class will be recording their measurements as they work. If you have maker journals, this is a great opportunity for students to record there. You may also choose to use the example chart found in the student resources tab.

**Reflect:**

If time allows, students may benefit from sharing their findings.

- Ask for example of measuring tools that worked well, and those that did not work well.
- Ask students if they had any very different measurements from classmates. Should this be the case, it is a perfect opportunity for students to work out what went wrong, so that the class can avoid this error in future measurements.