vocabulary
Maths vocabulary for age 9
Key words and phrases children around age 9 need to hear, use and understand.
Quick answer
By the end of this page, you'll know the most important maths words you need to understand and use when solving problems and talking about maths – from addition and subtraction to fractions, shapes, and data.Learning outcome
By the end of this page, you will understand and use key maths vocabulary that helps you solve problems and talk about maths clearly. Success signs:- You can explain what "product", "quotient", "numerator", and "denominator" mean
- You can use words like "perimeter", "area", "symmetry", and "probability" in a sentence
- You can describe shapes using terms like "vertices", "edges", and "faces"
- You can understand and use words like "mean", "mode", and "range" when talking about data
Why this matters
Maths vocabulary is like the building blocks of understanding. When you know the right words, you can talk about maths more clearly, solve problems better, and understand what teachers and books are asking you to do. Whether you're helping with homework, playing a maths game, or working out how much pizza to share with friends, knowing the right words makes everything easier.How it works
Learning maths vocabulary is like learning a new language. You don’t just memorise words – you connect them to what they mean and how they work in real life. We’ll go through important words in different areas of maths, like numbers, shapes, data, and operations. We'll show you how to use them in sentences, and give you fun ways to remember them.Examples you can see
Let’s look at some of the most important maths words you’ll meet around age 9, and how to use them: Addition:- Sum – The answer to an addition problem. Example: 4 + 5 = 9. The sum is 9.
- Plus – The word used for addition. Example: 3 plus 6 equals 9.
- Increased by – A way to say "add". Example: If a box has 7 apples and you get 3 more, it is increased by 3.
- Difference – The answer to a subtraction problem. Example: 10 - 3 = 7. The difference is 7.
- Minus – The word used for subtraction. Example: 12 minus 4 equals 8.
- Decreased by – A way to say "take away". Example: If you had 10 sweets and ate 3, you decreased by 3.
- Product – The answer to a multiplication problem. Example: 5 × 6 = 30. The product is 30.
- Times – The word used for multiplication. Example: 4 times 3 is 12.
- Repeated addition – Multiplication is like adding the same number many times. Example: 3 × 4 = 3 + 3 + 3 + 3 = 12.
- Quotient – The answer to a division problem. Example: 15 ÷ 3 = 5. The quotient is 5.
- Divided by – The word used for division. Example: 10 divided by 2 is 5.
- Share equally – A way to think about division. Example: If you have 12 cookies and want to share them with 4 friends, you divide 12 by 4.
- Numerator – The top number in a fraction. Example: In 3/5, the numerator is 3.
- Denominator – The bottom number in a fraction. Example: In 3/5, the denominator is 5.
- Equivalent fractions – Fractions that are the same size. Example: 1/2 = 2/4.
- Vertices – The corners of a shape. Example: A triangle has 3 vertices.
- Edges – The lines where two faces meet. Example: A cube has 12 edges.
- Faces – The flat surfaces of a shape. Example: A cube has 6 faces.
- Perimeter – The distance around a shape. Example: A square with sides of 5 cm has a perimeter of 20 cm.
- Area – The space inside a shape. Example: A rectangle that is 4 cm by 3 cm has an area of 12 cm².
- Mean – The average. Example: The mean of 4, 6, and 8 is 6.
- Mode – The most common number in a set. Example: In 2, 3, 3, 5, the mode is 3.
- Range – The difference between the biggest and smallest numbers. Example: In 2, 5, 8, 10, the range is 8.
Try it as a mini adventure
Imagine you are a maths explorer on a treasure hunt. You have a map that tells you to go to a spot where you’ll find clues. But the clues are written in maths words! Step 1: You find a clue that says: “Add 5 and 3 to find the first number.” What does that mean? The sum of 5 and 3 is 8. Step 2: You see a second clue: “If you have 10 sweets and eat 4, how many are left?” You need to subtract. The difference is 6. Step 3: You come to a box with a lock. The clue says: “The answer is the product of 6 and 4.” What number do you need to unlock it? The product is 24. Step 4: You see a fraction on a stone: “This is 1/4 of the treasure.” What does that mean? It means one part out of four equal parts. Step 5: You find a shape with 6 faces, 12 edges, and 8 vertices. What shape is it? A cube! Step 6: You collect data from 5 friends on how many books they read. The numbers are 3, 5, 5, 7, 8. What is the mean? The mean is 5.8. You’ve used lots of maths words to solve the treasure hunt! Now you’re ready to use these words in your everyday life.Common mistakes
- Mistake: Thinking that "product" means "addition" or "sum". Why it happens: The words sound similar. Fix: Remember: Product = multiplication. Sum = addition.
- Mistake: Mixing up "numerator" and "denominator". Why it happens: They are both part of a fraction and can be confused. Fix: The numerator is on top. The denominator is on the bottom.
- Mistake: Saying "divided by" when you mean "times". Why it happens: The words "divided" and "times" can be mixed up in your head. Fix: Use a picture or real example. 12 ÷ 4 = 3, but 12 × 4 = 48.
- Mistake: Confusing "mean" and "median". Why it happens: Both are about averages. Fix: Mean = add all numbers and divide. Median = the middle number.
Parent and carer guide
As a parent or carer, you can help your child learn maths vocabulary by:- Using the words in everyday conversation. For example, “How much more do we need to add to get 20?”
- Playing games that use the words. For example, "What's the product of 7 and 8?"
- Encouraging your child to explain their thinking. Ask: “How did you work that out?”
- Reading maths books or solving puzzles together to see the words in context.
- Not worrying if they make mistakes – it's part of learning!
Practice questions
- What is the sum of 12 and 8?
- What is the product of 9 and 6?
- What is the quotient when 36 is divided by 6?
- What is the numerator in the fraction 5/9?
- What is the perimeter of a square with sides of 4 cm?
- What is the mean of 4, 6, and 10?
- How many vertices does a hexagon have?
- What is the difference between 25 and 17?
- 20
- 54
- 6
- 5
- 16 cm
- 6.67
- 6
- 8
FAQ
What is the difference between a sum and a product?
The sum is the answer to an addition problem, and the product is the answer to a multiplication problem.
Why is it important to know maths vocabulary?
Knowing maths vocabulary helps you understand what a problem is asking and how to solve it. It also helps you talk about maths clearly with others.
How can I help my child learn maths words at home?
You can use everyday situations to talk about maths words, play games with numbers, and encourage your child to explain their thinking.
What are some common maths words for shapes?
Common shape words include: vertices, edges, faces, perimeter, area, symmetry, and diameter.
How do I know if a child understands maths vocabulary?
You can tell by how they use the words in sentences, solve problems, and explain their answers. If they can use the words in context, they understand them.