Teaching Measurement in Kindergarten: Hands-On Lessons and Centres for Length

Length is one of my favourite measurement concepts to teach in Kindergarten because children can see and test it everywhere. Which block tower is taller? Is a marker longer than a crayon? Whose play dough snake is the shortest?

I originally shared the lessons from my classroom in 2015. I updated this post in 2026 with more centre ideas and notes about how I would connect these activities to the 2026 Ontario Kindergarten curriculum.

What does the 2026 curriculum say about length?

Ontario’s Kindergarten measurement expectations ask children to describe different ways objects can be measured (A10.1) and compare the length, area, mass, and capacity of objects using concrete materials (A10.2). For length, I want children to handle objects, compare them, and explain what they notice using words such as longer, shorter, taller, and the same length. You can read the curriculum here.

The new expectations no longer explicitly mention measuring with repeated non-standard units. You’ll still see counting bears and snap cubes in some of my centres: they’re engaging tools for exploring different ways to measure, and they invite counting and conversation. I still teach and offer opportunities to practise unit iteration. When documenting learning for A10, though, I focus on how a child compares and describes length

Here’s how I introduce length and extend the learning through centres.

Start with longer and shorter

I introduce short, shorter, long, and longer with objects children can move and compare. One simple whole-group activity uses strips of construction paper. Children tear a strip into two pieces, decide which piece is longer, and help add the pieces to a class chart.

When comparing two objects directly, I show children how placing them side by side and lining up one end makes the difference easier to see. Then I ask, “Which is longer? How can you tell?” After a few comparisons together, I show a craft stick to the students and invite a few students to find something that is longer and something shorter in the classroom.

Students are invited to hunt and record their observations at centre time as well. They can draw, write or draw and label.

Compare our names

Names make a meaningful comparison because children are already curious about the letters in their own names and their friends’ names. In my classroom, I have students stamp letters in boxes on paper strips a day before the lesson.

During the lesson on Day 2, we order the names from shortest to longest. We start by ordering the names on the carpet so we can move them around easily and once the order is complete we glue it on the chart below.

I also made name trains with one linking cube for each letter.

During centres, children compared their train with a friend’s and explained what they noticed. Some questions I ask while I observe this centre are: “Which name train is longer? Are any the same length? How can you show me?” Children may notice both the number of letters and the physical length of the trains.

If you use paper name strips, make the letter boxes the same size and line up the strips at one end when you compare them. I have also used paint chips in the past and my students loved exploring with them!

I still like to offer a recording page for children who want to draw or write about their comparison, while keeping the building and conversation at the centre of the activity.

One year I took photos of them exploring the centre, added the photo to the worksheet below and had them complete it the next day in small groups.

Make play dough snakes

This was always a popular centre! I set out play dough and invited children to make three or more snakes, then arrange them from shortest to longest. Some children wanted to make many more. We talked about how they decided where each snake belonged and what might happen if they made one a little longer.

You can use a mat as an invitation or simply place the play dough on a tray. Ask children to line up the snakes and check their order. Adding small loose parts to decorate them with also provides opportunity for fine motor development and an opportunity to show patterning.

Offer non-standard measurement materials

Once children have compared lengths directly, I also introduce non-standard measurement and add familiar materials such as counting bears, snap cubes, and paper clips. These offer another way to explore length and a developmentally appropriate way to record length during play and inquiry.

For a foot investigation, children trace and cut out a shoe, then arrange counting bears along the cut-out.

In another centre, they place cubes along coloured tape lines or use a material of their choice to investigate picture cards.

I might ask, “Which line is longer?” or “What happens if you use a different material?”

When I first wrote this post, I described measuring a foot with bears as a summative assessment and focused on rules such as leaving no spaces. I would use it differently now. The bear count can be interesting, but my notes about A10 would focus on what children notice and explain when they compare lengths. A child might point to two cut-outs and say, “This one is longer,” then show how they checked.

Try a longer-or-shorter centre

At the Which Is Longer? centre, children look at two pictured sets of objects or build them with the provided materials. They decide which is longer and I encourage them to tell a table mate how they know. A recording page is available as an option, but children can show their thinking by simply lining up and comparing the objects, too.

If a child gives an answer based on which item looks bigger, I ask them to put the objects beside each other and look at the length specifically. That’s often all it takes to prompt a useful conversation.

What should I observe and document?

During a lesson or centre, I listen for how children use comparison words and how they check an idea with concrete materials. These questions help make their thinking visible:

• “Which one is longer? How can you tell?”
• “What could you do to check?”
• “Are any the same length?”
• “Can you put these in order and explain your choices?”

A quick note about a child’s words or a photo of the objects they arranged can capture more of their thinking than a number on a recording sheet alone.

If my teaching partner or I haven’t observed a child comparing lengths by the end of the unit, I will meet briefly with the child to compare two objects and ask how they know which is longer. If they are not able to, I can use this information to create a small group to review and practice this measurement language with them.

Want done for you math assessments aligned to the 2026 curriculum? Find them here: https://apinchofkinder.com/product/ontario-math-assessment-system/

More measurement ideas and ready-to-use centres

Length is one part of the 2026 measurement expectations. For ideas about mass, capacity, and exploring area through play, see my Teaching Capacity and Mass in Kindergarten: Hands-On Measurement Ideas post.

Area is included in the 2026 curriculum, but I haven’t included a stand-alone area lesson or centre in my measurement unit. I find children often explore area naturally during play and inquiry — for example, by covering two shapes with tiles and noticing which covers more space. Educators can use those conversations and observations as evidence of children’s ability to describe and compare area.

Want the ready-to-use activities? My printable measurement unit includes the length lessons and centres shown here, plus activities for mass and capacity. You can also explore measurement with the digital slides, or get both as part of the year-long Ontario Kindergarten Math System.

You can see all three options below.

I hope you found these ideas helpful!

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