> ## Documentation Index
> Fetch the complete documentation index at: https://help.edzo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Ruler Block

> Learn how to use Ruler blocks to display interactive measurement rulers in your resources.

The **Ruler** block displays a realistic measurement ruler with customizable units, length, and markings. Use it to demonstrate measurement concepts, show specific lengths, or provide a visual reference for measurement activities.

This is a display block for teaching and demonstration. Learners can view the ruler but aren't assessed on using it.

<Info>
  For assessable measurement activities where learners drag endpoints to measure objects, use the [Ruler Question](/creating/resources/question-blocks/ruler-question) block instead.
</Info>

## When to use Ruler blocks

Ruler blocks work well for:

* Demonstrating how to read a ruler
* Showing specific measurements as visual examples
* Teaching metric and imperial units of length
* Providing a reference ruler alongside question content
* Illustrating measurement concepts like half marks and intervals

## Settings

### Measurement settings

<ParamField path="Unit" default="Centimeters" type="select">
  The unit of measurement displayed on the ruler:

  * **Centimeters**: Metric centimeter markings
  * **Inches**: Imperial inch markings
  * **Millimeters**: Metric millimeter markings
</ParamField>

<ParamField path="Length" default="12" type="input">
  The total length of the ruler in the selected unit.
</ParamField>

<ParamField path="Start at" default="0" type="input">
  The starting value on the ruler. Use a value other than 0 to show a portion of a ruler.
</ParamField>

### Display settings

<ParamField path="Show half marks" default="true" type="switch">
  When enabled, displays half-unit tick marks on the ruler.
</ParamField>

<ParamField path="Show measurement numbers" default="true" type="switch">
  When enabled, displays numeric labels along the ruler.
</ParamField>

<ParamField path="Size" default="Medium" type="select">
  The display size of the ruler:

  * **Small**: Compact display
  * **Medium**: Standard display
  * **Large**: Larger display for projection or emphasis
</ParamField>

### Markers and objects

You can add markers at specific positions on the ruler to highlight particular measurements. You can also place objects along the ruler to show items being measured.

An optional measurement image can be placed alongside the ruler for realistic measurement scenarios.

## Tips for teachers and parents

**Best practices:**

* Start with centimeters for metric-based curricula or inches for imperial
* Hide measurement numbers for more challenging reading activities
* Use markers to highlight specific values or benchmark measurements
* Place objects on the ruler to show real-world measurement scenarios
* Set a non-zero start value to teach that measurement doesn't always begin at 0
* Pair with Ruler Question blocks to create teach-then-assess sequences

## Related blocks

* [Ruler Question](/creating/resources/question-blocks/ruler-question): Assessable version where learners measure objects interactively
* [Thermometer](/creating/resources/math-blocks/thermometer): For temperature measurement displays