Chapter VII – Measuring the Length of Line Segments
The ability to measure length is one of the fundamental mathematical skills developed in early primary education. A child who can determine the length of an object or a line segment not only learns how to use measurement tools, but above all understands size relationships, develops spatial awareness, and builds logical thinking skills.
In grades 1–3, measurement should not be limited to written exercises in a notebook. It should primarily involve action, manipulation, comparison, and experimentation. Measuring with a ruler, comparing lengths using the body (for example steps), or creating one’s own measuring units are activities that help students fully understand the concept of length.
Korbo blocks perfectly support this stage of learning. Thanks to the variety of sizes and shapes of the elements (gears, cylinders, connectors, platforms), children:
can build line segments and measure them using self-made measuring units,
understand that length depends not only on the number of elements but also on their type,
learn to estimate, count, and compare lengths in real-life situations,
develop spatial thinking and organizational skills.
Activities involving length measurement with Korbo blocks teach children a practical approach to mathematics—one that is meaningful and applicable to everyday life.
After completing this chapter, the student:
understands the concept of length as a measurable property of a line segment or object using a unit of measure,
measures the length of straight line segments using standard units (for example a ruler) and non-standard units (for example blocks),
builds line segments of a given length using selected Korbo elements,
compares the lengths of different segments using the terms longer, shorter, and equal,
uses mathematical symbols >, <, = in the context of comparing lengths,
measures length using different units of measure, understanding that units may have different “values”,
creates and uses their own block-based “measuring tools” to measure the length of objects,
measures the length of straight and broken line segments and records them as a sum,
solves word problems related to length (for example “How much longer is segment A than segment B?”),
applies length measurement when building spatial structures and routes (for example determining a path from point A to point B).
1. Measuring Length with a Korbo Segment
Objective:
Introducing the concept of the length of a line segment and a unit of measurement.
Materials needed:
Korbo cylinders and straight connectors, masking tape
Procedure:
The teacher marks line segments of different lengths on the floor using masking tape. Students work in groups (for example red, blue, green, yellow). Each group connects cylinders in their group’s color using connectors to create a “measuring unit” that should match the length of the marked segment. Then they count how many cylinders were used to measure the length.
Students present the result in the form:
“Length = 3 cylinders.”
Variants:
Changing the unit: measuring with gears placed next to each other along the tape line
Comparison: comparing the results with a ruler or a tape measure
2. Which Segment Is Longer?
Objective:
Comparing the lengths of different line segments.
Materials needed:
Gears, cylinders, connectors
Procedure:
Children build two line segments using cylinders and straight connectors.
Next, they compare the lengths by placing the segments next to each other or by counting the elements.
Variants:
Introducing the symbols >, <, =
Building segments with the same number of elements, for example one segment made of connected cylinders, another made of gears placed next to each other, and another made of connected platforms
3. Building to a Given Length
Objective:
Creating constructions of a specified length.
Materials needed:
All types of Korbo blocks, a ruler (or paper meter sticks)
Procedure:
The teacher gives a length (for example 35 cm). Children build a line segment of that length by placing blocks next to each other, using any elements they choose.
Variants:
Team activity: which group gets closest to the target length
4. From Point A to Point B
Objective:
Measuring the length of a line segment between two points.
Materials needed:
A platform with marked points A and B, connectors
Procedure:
Children build a route from point A to point B and then calculate its length by counting how many elements were used to connect the two points (for example from a table to a door). The result can be written as a calculation (for example 25 cylinders plus 15 gears plus 5 connectors equals 45 elements).
Variants:
Different routes between the same points
The shortest or longest possible route, or replacing elements to use as few as possible
5. Block Measuring Line
Objective:
Building a custom measuring tool from blocks and using it to measure.
Materials needed:
Cylinders and connectors or for example four platforms
Procedure:
Students create a measuring line from the elements (for example 1 unit = 1 cylinder). Then they measure various objects in the classroom or their own constructions.
Variants:
Comparing the lengths of different “measuring tools”
Converting the results into centimeters using a paper 1-meter measure
6. Length Chain
Objective:
Adding the lengths of consecutive line segments.
Materials needed:
Platforms, gears, cylinders, connectors
Procedure:
Children build three short line segments and measure each one separately. Then they connect them into one whole segment and measure the total length.
Variants:
Building the longest possible measuring tool using all available cylinders and connectors
7. Length and the Number of Elements
Objective:
Understanding that length is not always equal to the number of elements.
Materials needed:
Gears, cylinders, connectors of different lengths
Procedure:
Children build two line segments using a different number of elements (for example 5 gears versus 3 cylinders). They measure and compare them, discovering that “more elements” does not necessarily mean “longer”.
Variants:
Observing the relationship: length of one element × number of elements
Recording the result as a multiplication expression
8. Measuring Curves
Objective:
Estimating the length of a broken line.
Materials needed:
Cross connectors, cylinders, platforms
Procedure:
Children build a broken line (for example in the shape of the letter “L”) and measure the length of each part, then add the results. Different units can be used (blocks, a ruler).
Variants:
Recreating the route as a robot (for example 10 cylinders = 10 steps) and checking how long the line would be if each element represented one step
Comparing broken lines and straight segments with the same total length or made from the same number of elements arranged in a straight line
9. Your Step, Your Length
Objective:
Comparing lengths using non-standard units (for example step length).
Materials needed:
Platforms used as a path, masking tape, a measuring tape, cylinders and connectors
Procedure:
The teacher marks a line segment on the floor using tape. Children measure how many steps or forearms are needed to walk along the route. Next, they build their own measuring tool. They can create their own “step unit” from three connected cylinders and check how many such units fit into the taped segment. Children can then change the “step unit” to a larger or smaller one and compare again.
Variants:
Comparing their own results (steps, forearms) with those of other children
Measuring different routes in the classroom
10. The Length Game
Objective:
Applying the concept of length through play.
Materials needed:
Blocks, a die, task cards
Procedure:
A board-style game: a child rolls the die and builds a line segment using as many elements as the number rolled. The class then checks which segment is the longest. Segments can also be built vertically by placing a platform as the base. Two dice can be used to practice addition, or in older classes, multiplication.
Variants:
Game version: the teacher marks a longer line on the floor with masking tape. Children roll the die and are told how many elements they must connect in each round. The winner is the first person to build a measuring tool equal in length to the taped route.
Additional challenges, for example: if your measuring tool consists of five elements in the same color, you may add two extra blocks.