Mathematics Class 2 - Number Sense Notes

Number Sense

Welcome to the chapter on Number Sense for Class 2. In this chapter, you will learn about numbers, counting, comparing, and ordering numbers. By the end of this chapter, you will be able to read, write, and understand numbers up to 100 and beyond!

Introduction

Number sense means understanding numbers and how they work. It helps us count, compare, and use numbers in daily life.

Counting Numbers

We use numbers to count things around us. Numbers go on and on, but let’s start with numbers up to 100.

• Count from 1 to 100.
• Count objects like pencils, books, or apples.

Reading and Writing Numbers

Numbers can be written in figures (like 23) and in words (like twenty-three).

• 15 – Fifteen
• 42 – Forty-two
• 99 – Ninety-nine

Comparing Numbers

We compare numbers to see which is bigger or smaller.

• 45 is greater than 32.
• 18 is less than 27.
• Use signs: > (greater than), < (less than), = (equal to).

Ordering Numbers

We can arrange numbers in order from smallest to biggest (ascending) or biggest to smallest (descending).

• Ascending: 12, 23, 34, 45
• Descending: 45, 34, 23, 12

Place Value

Each digit in a number has a place value. In 56, 5 is in the tens place and 6 is in the ones place.

• Tens and ones help us understand numbers better.
• Example: 47 = 4 tens and 7 ones

Fun Activity: Number Hunt!

Look around your home or classroom and find numbers on clocks, books, or calendars. Write down the biggest and smallest number you find!

Summary

• Numbers help us count, compare, and order things.
• We can write numbers in figures and words.
• Place value tells us the value of each digit.

Practice Questions

1. Write the number name for 58.
2. Which is greater: 76 or 67?
3. Arrange these numbers in ascending order: 23, 12, 45, 34.
4. What is the place value of 3 in 39?
5. Write the smallest number between 21, 19, and 25.

Challenge Yourself

• Write all the numbers from 90 to 100.
• Find three things at home with numbers on them and write those numbers.

Did You Know?

• Zero means nothing, but it is very important in math!
• Numbers are used everywhere—in games, money, and time!

Glossary

• Number: A symbol that shows how many.
• Place Value: The value of a digit based on its place in a number.
• Ascending: Smallest to biggest.
• Descending: Biggest to smallest.

Answers to Practice Questions

1. Fifty-eight
2. 76
3. 12, 23, 34, 45
4. 3 tens
5. 19

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Practice number sense every day to become a math champion!