What is a Number Sentence?

S0-SA1-0291

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A number sentence is a mathematical statement that shows the relationship between numbers using symbols like +, -, x, ÷, =, <, or >. It's like a complete sentence in English, but instead of words, it uses numbers and math symbols to tell a story or state a fact.

Simple Example

Quick Example

Imagine you have 5 ladoos, and your friend gives you 3 more. If you want to write this as a math fact, you would write '5 + 3 = 8'. This '5 + 3 = 8' is a number sentence because it uses numbers and symbols to show a complete idea.

Worked Example

Step-by-Step

Let's say you have 100 rupees and you want to buy a packet of chips for 20 rupees.
---First, identify the numbers involved: 100 (your money) and 20 (cost of chips).
---Next, identify the operation: You are spending money, so it's subtraction.
---Then, identify what you want to find: How much money is left.
---Put it all together with an equals sign: 100 - 20 = 80.
---This '100 - 20 = 80' is your number sentence.
---It tells the complete story of your transaction.
---Answer: The number sentence is 100 - 20 = 80.

Why It Matters

Number sentences are the basic building blocks of all mathematics. Understanding them helps you solve problems in algebra, geometry, and even coding. Engineers use number sentences to design bridges, and financial analysts use them to manage money.

Common Mistakes

MISTAKE: Writing '5 + 3' and stopping there | CORRECTION: A number sentence must be a complete thought, usually with an equals sign or an inequality. '5 + 3 = 8' is a number sentence, but '5 + 3' is just an expression.

MISTAKE: Confusing number sentences with word problems | CORRECTION: A word problem is a story that you need to translate into a number sentence. The number sentence is the mathematical way of writing that story.

MISTAKE: Forgetting the operation symbol or the equals sign | CORRECTION: Every number sentence needs at least one operation symbol (+, -, x, ÷) and usually an equals (=) or inequality (<, >) sign to make it a complete statement.

Practice Questions

Try It Yourself

QUESTION: Write a number sentence for '7 added to 4 makes 11'. | ANSWER: 7 + 4 = 11

QUESTION: Your mom gave you 50 rupees. You spent 15 rupees on a samosa. Write a number sentence to show how much money you have left. | ANSWER: 50 - 15 = 35

QUESTION: A cricket team scored 180 runs in the first innings and 210 runs in the second innings. What number sentence shows their total score? | ANSWER: 180 + 210 = 390

MCQ

Quick Quiz

Which of the following is a number sentence?

6 + 2

8 - 3 = 5

10 x

Four plus five

The Correct Answer Is:

Option B, '8 - 3 = 5', is a complete mathematical statement with numbers, an operation, and an equals sign. The other options are either incomplete expressions or written in words.

Real World Connection

In the Real World

When you check your mobile data usage, your phone might show '2 GB used out of 5 GB remaining = 3 GB total'. This is a number sentence in action! Or, when a shopkeeper calculates your bill, they're creating number sentences like 'item1 price + item2 price = total bill'.

Key Vocabulary

Key Terms

OPERATION: A mathematical action like addition, subtraction, multiplication, or division | EQUAL SIGN (=): A symbol showing that two values are the same | INEQUALITY (<, >): Symbols showing one value is greater than or less than another | EXPRESSION: A part of a number sentence without an equals sign (e.g., 5 + 3)

What's Next

What to Learn Next

Now that you understand number sentences, you can move on to 'Solving Simple Equations'. You'll learn how to find missing numbers in a number sentence, which is a fundamental skill for all higher math!