measurement
Length for children
Measure how long or tall objects are using non-standard and standard units.
Quick answer
Length is how long or tall something is. You can measure length using standard units like centimetres (cm) or metres (m), or non-standard units like paper clips or footsteps.Learning outcome
By the end of this page, you will be able to measure how long or tall things are using both standard and non-standard units, and you will know when to use each type of measurement. Success signs:- You can choose the right unit to measure different objects
- You can line up your measuring tools correctly
- You can compare lengths using words like "longer", "shorter", "taller", "wider"
- You can estimate and then check how long something is
Why this matters
Length helps us understand how big or small things are. This is useful in many ways:- When you're building with LEGO or blocks, you need to know how long each piece is
- When you're cooking, you need to know how long your recipe instructions are
- When you're playing football or running races, you measure how far you go
- When you're shopping, you might need to know how long a ribbon is
- When you're planning a garden, you measure how long your flower beds are
How it works
Measuring length means comparing how long or tall something is to a unit of measurement. Here are the simple steps:- Choose your unit – Decide if you want to use standard units (like cm or m) or non-standard units (like paper clips or your hand)
- Place your unit – Put your measuring tool at the start of the object
- Count the units – Count how many times your unit fits along the object
- Record your answer – Write down how many units long it is
Examples you can see
Let's imagine you're going on a treasure hunt. You find a map that shows how far you need to walk to find the treasure. Example 1: Using non-standard units You use your handspan to measure the length of a table.- First, you put your hand at the start of the table
- Then you place your hand again at the end of the table
- You count: 1, 2, 3, 4 handspans
- The table is 4 handspans long
- You start at the wall
- You move the metre stick along the wall
- You count: 1, 2, 3, 4, 5 metres
- Your bedroom is 5 metres long
- Red pencil is longer than blue pencil
- You can write: 12 cm > 10 cm
Try it as a mini adventure
Adventure: The Great Garden Measuring Challenge You are the gardener in a magical garden where all the plants grow in different sizes. Your job is to measure and compare all the plants.- First plant: A sunflower that is 150 cm tall. You measure it with a metre stick.
- Second plant: A tomato plant that is 75 cm tall. You measure it with a ruler.
- Third plant: A flower that is 25 cm tall. You measure it with a tape measure.
- Fourth plant: A small herb that is 10 cm tall. You measure it with your handspan.
- Which plant is the tallest?
- Which plant is the shortest?
- How much taller is the sunflower than the tomato plant?
- How many handspans tall is the small herb?
Common mistakes
- Mistake: Not starting at the very beginning of the object when measuring.
Why it happens: The child might start measuring from the middle or from the end.
Fix: Always start at the very edge of the object and make sure the measuring tool is aligned properly. - Mistake: Not keeping the measuring tool straight.
Why it happens: The child might bend or twist the ruler or tape measure.
Fix: Keep the measuring tool flat and straight along the object. - Mistake: Counting the starting point as one.
Why it happens: Children sometimes count the first unit as "1" instead of "0".
Fix: Explain that you start counting from the first unit, so the first unit is "1", not "0".
Parent and carer guide
As a parent or carer, here are 5 ways you can help your child learn about length:- Measure together – Ask your child to help you measure the length of the dining table, the height of a door, or the width of a bookshelf.
- Use different units – Try measuring the same object using both standard units (like cm) and non-standard units (like paper clips).
- Compare lengths – Ask your child to compare how long different items are. For example, "Is your pencil longer than your pen?"
- Play measurement games – Create a game where you measure different items around the house and see who can find the longest or shortest object.
- Encourage estimation – Before measuring, ask your child to guess how long something might be. Then measure to see how close they were.
Practice questions
- How many centimetres is a standard pencil? Answer: About 18 cm
- What unit would you use to measure the length of a swimming pool? Answer: Metres
- Which is longer: 100 cm or 1 m? Answer: They are the same (1 m = 100 cm)
- How many handspans are needed to measure a 50 cm book? Answer: About 5 handspans (assuming 10 cm per handspan)
- What is the difference in length between a 75 cm plant and a 50 cm plant? Answer: 25 cm
FAQ
What is the difference between standard and non-standard units of measurement?
Standard units are the same for everyone, like centimetres (cm) or metres (m). Non-standard units are things you find around your home, like paper clips or your handspan.
Why do we use standard units?
Standard units help us compare measurements accurately. If everyone uses the same units, we know exactly how big or small something is.
How can I teach my child about length at home?
You can measure everyday objects like toys, books, or furniture. Ask your child to compare lengths, estimate measurements, and use both standard and non-standard units.
Can I measure anything with a ruler?
Yes, you can measure anything that has a straight edge with a ruler. You just need to make sure the ruler is lined up correctly.
What are some real-life examples of measuring length?
Examples include measuring how tall you are, how long a piece of string is, how far you walked, or how long a cake is before baking it.