What Is a Ruler?
A ruler is a measuring instrument used to determine the length or distance of an object. It typically features straight edges with markings or units of measurement, such as inches or centimeters, enabling precise measurements. Rulers are commonly made from materials like plastic, metal, or wood and are essential tools in various fields, including education, construction, and design.
Measurement is an integral part of everyday life, whether estimating travel time, shopping expenses, or crossing a puddle's width. Measurements include time, weight, length, and capacity. Metric units like millimeters, centimeters, and meters are used for length, while customary units like inches, feet, and yards are common in the USA. In geometry, technical drawing, and civil engineering, lengths are crucial, and rulers serve three main purposes: measuring, drawing straight lines, and providing a guide for cutting.
Types of Rulers
Let’s discuss types of rulers based on their specific purpose. Here are a few common types of rulers:
- Standard Ruler: Measures 12 inches (30 centimeters) and is commonly used for everyday measurements in schools and homes.
- Flexible Ruler: Can bend and curve, perfect for measuring irregular shapes, often made from plastic or fabric. Flexi rulers can create wavy lines in addition to straight measurements.
- Digital Ruler: An electronic device that displays measurements on a screen, offering accuracy and adjustable units
- Triangular rulers: Triangular rulers are useful for drawing horizontal, vertical, and inclined lines.
- Architect's Scale: Designed for architects and engineers, it has multiple scales for converting measurements between different units.
- Engineer's Scale: Similar to the architect's scale, but uses a base-10 system, making it suitable for technical drawings.
Let’s take a look at some commonly used rulers and their measurement markings.
12-inch ruler: One of the most common rulers is a 12-inch ruler.
This can be used to measure various objects that are available in the classroom such as the length of the table, bench, duster etc.
Centimeter ruler: When it comes to metric measurements, the ruler in cm and ruler in mm are most common.
Rulers marked with inches and cm: In general, one side of the rulers used at this level will be marked in centimeters and the other side in inch measurements.
Types of rulers based on the material used include metal ruler, plastic ruler, wooden ruler, etc.
How To Read a Ruler
- Identify the units: Determine if the markings are in inches or centimeters.
- Find the starting point: Locate the zero on the ruler.
- Observe the markings: To read a ruler, begin by comprehending the meaning of each tick mark. Check for fractions like 1/2, 1/4, 1/8, or 1/16 (inches) or millimeters (centimeters).
- Find the length of an object: Align the ruler's zero with one end and read the marking at the other end. The marking you read shows the object's length or distance between two points.
How To Measure Length Using a Ruler
When measuring length using a ruler, one of the most important things is to line up the initial mark of the ruler with the tip of the object to be measured. A ruler is read from left to right, and the number aligned with the end of the object or distance represents its measurement.
The given images show the ruler game that involves measuring the length of everyday objects with the rule.
Example 1: The length of the given crayon is 18 cm.
One end is lined up with 0 cm.
Other end is at 18 cm.
Length of crayon = 18 cm - 0 cm = 18 cm
Example 2: The length of the below crayon is not 18 cm as the bottom end of the crayon doesn’t line up with the zero of the ruler.
One end is lined up with 2 cm.
Other end is at 18 cm.
Length of crayon = 18 cm - 2 cm = 16 cm
Are you looking for ‘Reading a Ruler Games’ for kids? Make sure to explore these amazing Games for kids on Measuring Lengths and excel in measurement skills!
Measuring Halves and Fourths of a Whole on Ruler
In the next level, more accurate rulers marking halves and quarters are introduced to kids. Children have a basic knowledge of fractions which can be applied here. They already know that two halves or four-fourths make a whole. Children have already learned how to plot or read fractions on a number line. This would help them relate the ruler markings with the number line.
When measurements on a ruler are till the half of a whole, each whole is equally divided into two. In an online 12 inch ruler, the first mark after 0 would be at ½, the second one at 1, the fourth one at 1½ and so on. There would be 24 marks on the 12-inch ruler.
When measurements on a ruler are till the quarter of a whole, each whole is equally divided into four. In a one inch ruler, the first mark after 0 would be at ¼, the second one at ½, the third one at ¾, and the fourth one at 1. In a similar way, each whole is divided into 4.
The below ruler measures halves and fourths of an inch:
Usually, 1/4 on a ruler is marked with equal heights but shorter than the ½ mark.
When it comes to metric unit rulers, a unit measurement, a centimeter, would be subdivided into 10 small lines, each measuring one millimeter.
Worksheets for 3rd graders available at SplashLearn for measuring objects using a digital ruler start with easier ones that measure to the nearest inch. Gradually it advances to measure nearest to the halves and quarters.
Comparing Lengths Using a Ruler
The concept of length is introduced by comparing two objects of different sizes. Once children are comfortable with the concept as well as the vocabulary of longer/shorter, more of/ less of etc, they can compare and arrange three or more similar objects.
Example 1: The games include examples that help children identify shorter or longer objects.
Example 2: Children learn about the terms - shortest, longest, with the help of colorful visuals and everyday items
Example 3: The basic method of measuring is introduced at this stage using multiple copies of a shorter object. For example, in the below picture the length of the pencil is measured using the number of coins.
That is, the length of the pencil is equal to that of 5 coins. One needs to be careful that the shorter object should be lined up properly with the longer object. There shouldn’t be any gap or overlap within the measuring objects. This lays the foundation for the ruler measurements.
Estimation of Length Using a Ruler
An estimation is a reasonably close guess or approximation of an object.
Kids learn about the estimated length of the body parts of humans such as the arm is about a foot long, arm span is about a meter etc. This helps them get a clearer picture of the length than using the exact measurements with the ruler.
By then kids have an idea about various units and how much they measure. So, kids can apply this knowledge on estimating the length of the objects that they see around them.
Children also learn which measure and unit to be used for an accurate measurement of a given object.
The estimation of lengths in metric units as well as customary units are dealt in separate sections in SplashLearn with a wide range of self-explanatory math problems. Check out these fun Estimate Lengths Games for more details!
Ruler and Measurement Activities for Kids
- Comparative Analysis: Kids compare objects of different sizes to understand differences in size.
- Preschool Games: Engaging learning games with colorful pictures create interest in measurement concepts.
- Problem-Solving Activities: Ordering three similar objects by size to fosters problem-solving skills.
- Hands-on Measurement: Using small measuring sticks, kids measure and compare object lengths as interactive group activities.
- Reading Measurements: Activities introduce kids to reading measurements on rulers.
- Real-life Measurement: Kids can experience measuring objects with actual rulers, exploring different metric and inch rulers.
- Online Resources: Utilizing online measuring tapes for printable rulers like centimeter and mm rulers for class activities.
Progression of Measurement Concepts with Ruler across Grades
| Grade | Concepts |
| Kindergarten | - Understand the concept of measurable attributes without actual measurement - Identify, describe, analyze, compare, and compose 2D and 3D shapes. (using informal language to describe their similarities, differences, parts) - Compare two objects with a shared measurable attribute to determine which one has "more" or "less" of that attribute and describe the difference between them. |
| Grade 1 | - Ordering similar objects based on length - Learn to measure and compare length using shorter objects laid end to end |
| Grade 2 | - Introduce different measuring devices (scale rulers, meter sticks, yardsticks, measuring tapes) - Learn to read rulers with pictorial examples - Measure and estimate lengths using units of inches, feet, centimeters, and meters - Solve word problems related lengths of objects (comparing and finding the difference) (Note: Students learn about the actual units of measurement starting from grade 2.) |
| Grade 3 | - Introduce ‘inch rulers’ marking halves and quarters of an inch - Measure lengths to the nearest halves and quarters using different rulers |
| Grade 4 | - Explore the relationship between units within the same system - Solve problems involving measurements and conversion of measurement units |
How Can Children Use the Concept of Measuring Length with Rulers in Real Life?
- Measuring Objects for Fit and Size: Children can use rulers to measure the length of objects, like books, toys, or their school supplies, to ensure they fit in specific spaces or bags. They can also engage in tape measure practice game activities for fun learning!
- Precision in Artwork and Crafts: They can use rulers to draw straight lines while doing artwork, crafts, or building structures, ensuring precision and accuracy.
- Accurate Measurements in Cooking and Baking: Rulers can help children understand measurements in cooking or baking, where specific ingredient quantities are crucial for a successful recipe.
- Practical Skills in DIY and Home Improvement: In DIY projects or home improvement tasks, children can measure materials accurately using rulers, enhancing their practical skills.
Benefits of Introducing Rulers to Kids through Games
- Fun Learning: Interactive ruler measuring games make using rulers enjoyable for kids, keeping them engaged while they learn about measurements.
- Practical Practice: Kids get to measure real objects in games, helping them understand length and size better.
- Better Measurement and Math Skills: Playing ruler games improves counting, adding, and understanding fractions, which are important math skills.
- Confidence Booster: Kids feel proud of their achievements in games and become more confident in using rulers in real life.
What Are 5 Best Fun Ruler Games and Activities for Kids?
Here’s a list of 5 best, fun and interactive Ruler games and activities for kids:
- Measure Length in Centimeters Game
- Measure Length in Inches Game
- Measure Length on a Ruler by Subtracting Game
- Measure Length in Inches by Subtracting Game
- Measure Length in Half Inches Game