"Who's taller?" "Which bag is heavier?" "Is there more juice in my glass?" Children ask measuring questions long before they meet a ruler. Measuring is about comparing: how long, how heavy, how much something holds. This article explains how children learn to measure, starting with direct comparison, then everyday units like hand spans and cups, and finally rulers and scales.
Three things children measure
- Length: long and short, tall and short, wide and narrow.
- Weight: heavy and light.
- Capacity: full and empty, holds more or less.
For each one, the learning path is similar: first compare two things directly, then put several in order, then measure with small units, and only later with standard tools.
Step 1: compare directly
- Line up the ends. To compare two pencils, put them side by side with one end lined up. A very common mistake is to compare without lining up the start, so the one that sticks out further looks longer.
- Back to back. To see who is taller, stand back to back on flat ground.
- One in each hand. Hold two objects and feel which pulls down more. Then check on a kitchen scale or a homemade balance (a coat hanger with a bag on each end).
- Pour and see. To compare two cups, fill one with water and pour it into the other. Does it overflow, or is there room left?
Step 2: put things in order
- Three pencils, shortest to longest. Then four or five.
- Heaviest to lightest. Compare objects two at a time. If the book is heavier than the apple, and the apple is heavier than the spoon, which is heaviest?
- Least to most. Put a little water in three glasses of the same size and order them.
Ordering helps children see that "longer" and "shorter" depend on what you compare with: the same pencil can be the longest in one group and the shortest in another.
Step 3: measure with everyday units
Before rulers, children can measure with things they can count:
- Length: hand spans, footsteps, blocks, paper clips, a piece of string.
- Weight: how many blocks balance the toy on a homemade balance?
- Capacity: how many cups of water fill the jug?
Two rules make these measurements fair:
- No gaps and no overlaps. Blocks lined up for measuring should touch, without spaces between them.
- Always the same unit. Don't mix big and small blocks in one measurement.
Then try something interesting: measure the table with your hand spans and with your child's. You'll get different numbers. Why? Because hands are different sizes. That's exactly why people agreed on standard units like centimetres and kilograms.
The traps to watch for
- Not lining up the start. Remind children to put both ends together on the same line.
- Tall, thin glasses. Pour the same water from a wide glass into a tall, thin one. Many young children think there is now more water because it's higher. Pour it back to check together.
- Big doesn't mean heavy. A big pillow is lighter than a small bag of rice. Let children feel it.
Step 4: rulers, scales and jugs (around ages 6–10)
- Start at zero. When using a ruler, line the object up with 0, not with the edge of the ruler or with 1.
- Read whole centimetres first, then half centimetres for older children.
- Kitchen scale and measuring jug. Cooking together gives real reasons to measure grams and millilitres.
| Age (approximate) | Activities |
|---|---|
| 4–5 | Comparing two things directly, words like longer, heavier, fuller |
| 5–6 | Ordering three or more things, hand spans and steps |
| 6–7 | Blocks and cups as units, no gaps and no overlaps |
| 7–10 | Rulers from zero, kitchen scales, measuring jugs |
In Dologi, "Put in order" puzzles in the Math topic ask children to arrange pencils from shortest to longest, weights from heaviest to lightest or glasses from least water to most.
In short
- Measuring starts with comparing: line up ends, stand back to back, hold one in each hand, pour.
- Ordering several things comes next, then measuring with everyday units.
- Fair measuring means no gaps, no overlaps and always the same unit.
- Rulers start at zero, and a tall, thin glass doesn't hold more just because it's taller.
Read more: Math with everyday things: counting, comparing and sharing at home