Teaching Measurement to Preschoolers: Tallest, Shortest, Biggest, Smallest

Long before children use rulers, they're measuring. "My tower is bigger than yours!" "I got more juice!" "Daddy is the tallest!" Young children are natural comparers, and those comparisons are the foundation of measurement — one of the core strands of early math.

In preschool, measurement isn't about inches and centimeters. It's about noticing attributes (how tall, how long, how heavy, how much it holds) and comparing them with the right words. Here's how to teach it in a way that sticks.

The big ideas of early measurement

1. Objects have attributes we can measure — height, length, weight, capacity.
2. We can compare two objects — which is taller, which is shorter.
3. We can order several objects — from smallest to biggest.
4. We can use a unit to measure — "My table is 6 blocks long."

Most preschoolers are working on the first three. Using non-standard units (blocks, paper clips, hands) comes toward the end of Pre-K and into kindergarten.

Start with vocabulary

Children need words to describe what they notice. Introduce these in pairs, and use them constantly during the day:

• Tall / short (height)
• Long / short (length)
• Big / small, large / little (size)
• Heavy / light (weight)
• Full / empty (capacity)
• Wide / narrow
• Taller / tallest, shorter / shortest, bigger / biggest

The "-er" and "-est" words are especially important. "Taller" compares two things; "tallest" picks one from a group. Many children mix them up, so model them clearly: "This tower is taller than that one. But this one is the tallest of all."

Hands-on activities

Tower comparisons

Children build towers with blocks or linking cubes, then compare. "Whose tower is taller?" Line them up side by side on the same starting line — a key idea children need to learn. If one tower starts on a book, the comparison isn't fair!

Line up by height

Gather stuffed animals, water bottles, or toy figures and have children arrange them from shortest to tallest. Then mix them up and try again.

Who's the tallest?

Take a photo of children standing back to back, or mark children's heights on a strip of paper taped to the wall. Children love seeing where they stand, and it's a meaningful comparison. Repeat midyear to show how much they've grown.

Nature walk comparisons

Collect sticks, leaves and rocks. Back inside, sort them: long sticks and short sticks, big leaves and small leaves, heavy rocks and light rocks.

Balance scale

A simple bucket balance is one of the best math tools you can own. Children predict which object is heavier, test it, and talk about what happened. "The apple went down, so it's heavier than the pinecone."

Fill it up

At the sensory table or water table, provide containers of different sizes. "Which one holds more? How many scoops will it take to fill?" This is capacity — the math of full and empty.

Measure with your body

"How many of your feet long is the rug?" "How many hands tall is the chair?" Children quickly notice that different people get different answers — which is exactly why we eventually need standard units like inches.

Snake measuring

Children make playdough snakes and compare them: longest, shortest, same length. Then measure each snake with paper clips or cubes.

Printable practice

Once children have lots of hands-on experience, paper activities can reinforce the concepts. A "Circle the tallest" page, for example, shows pairs of familiar objects in two sizes — a big and small box of crayons, a long and short pencil, a big and small bottle of glue, a backpack, scissors, a notebook — and children circle the tallest in each pair. Using school supplies children handle every day makes the comparison meaningful, because they can check with the real objects.

These pages come from our September Preschool Learning Book, which pairs a school-supply theme with measurement, counting, and letter practice. Laminate a page and it becomes a reusable dry-erase activity.

Try extensions with the same page:

• Circle the shortest instead.
• Color the bigger one.
• Find the real objects in the classroom and compare them.

Common misconceptions

"Taller means wider." Children may think a wider object is "bigger" even when it's shorter. Talk specifically about which attribute you're comparing.

Ignoring the starting line. Line objects up on a flat surface or tape line before comparing length or height.

Confusing "more" with "bigger container." A tall thin glass can look like it holds more than a short wide bowl. Pour water from one to the other to test it — children are fascinated.

Measurement across the day

• Snack: "Who has the longest carrot stick?"
• Blocks: "Can you build a tower taller than the shelf?"
• Outside: "Whose shadow is longest right now?"
• Cooking: Measuring cups and spoons introduce real units.
• Books: Many picture books explore size — look for books about giants, small creatures, and things that grow.

For parents

Measurement is everywhere at home. Compare shoes by size, line up cereal boxes by height, ask which bag of groceries is heavier, and let your child help measure ingredients when you cook. Mark your child's height on a door frame and talk about how they've grown.

For more everyday math, see building number sense and patterns, sorting and shapes.

Frequently asked questions

When do children start using rulers?

Most children use non-standard units (blocks, paper clips, hands) in late Pre-K and kindergarten, and move to rulers and inches in first or second grade. Comparing and ordering come first.

How can I make a 'circle the tallest' page reusable?

Slip it into a plastic sheet protector or laminate it, and give children a dry-erase marker. Wipe it clean and the page becomes a center activity for the whole month.

What's the difference between tall and long?

We usually say tall for things measured standing up (people, towers, bottles) and long for things lying down or measured end to end (snakes, trains, pencils on a table). Model both words clearly.