Chapter 2 — Place Value and Number Understanding
Numbers become easier to understand when we know how they are made. In the previous chapter, you learned how to count, read and compare numbers. Now we will look more closely at two-digit numbers.
In this chapter, you will learn about tens and ones and how they help us understand the value of each digit in a number. You will then use this knowledge to make, read, compare and order two-digit numbers.
Why This Chapter Matters
A number is not only a collection of digits. The position of a digit tells us its value.
For example, in 25, the digit 2 represents two tens, while the digit 5 represents five ones.
Understanding this idea gives you a strong foundation for working with bigger numbers and for learning addition, subtraction and other mathematical concepts later.
What You Will Learn
- How tens and ones make a two-digit number.
- How the position of a digit affects its value.
- How to make numbers using tens and ones.
- How to read and write two-digit numbers.
- How to compare two-digit numbers.
- How to arrange two-digit numbers in order.
Before You Begin
Before starting this chapter, you should be comfortable with counting numbers and recognising numbers in their correct sequence.
You should also understand that counting tells us how many objects there are.
If you need to revise these ideas, you can first complete the lessons in Chapter 1 — Numbers and Counting.
Understanding the Learning Sequence
The lessons in this chapter are arranged in a specific order. Each lesson builds on the idea learned in the previous lesson.
Following the lessons in this order will help you understand two-digit numbers step by step.
Lessons in This Chapter
Complete the lessons in the order shown below. Each lesson prepares you for the next one.
Important Ideas
- Ten ones make one ten.
- A two-digit number has a tens place and a ones place.
- The left digit represents tens.
- The right digit represents ones.
- The position of a digit determines its value.
- Tens and ones can be used to make two-digit numbers.
- Two-digit numbers can be compared and ordered.
Chapter Practice
After completing the lessons, try these activities to check your understanding.
- Find the tens and ones in 24.
- Make a number using 3 tens and 5 ones.
- Read the number 47 aloud.
- Compare 36 and 42.
- Arrange 25, 14 and 31 from smallest to largest.
Quick Revision
In this chapter, you will build a clear understanding of how two-digit numbers work.
You will learn how tens and ones form numbers, how to read and write those numbers, how to compare them and how to arrange them in the correct order.
Continue Learning
Start with Lesson 1 — Understanding Tens and Ones and complete the lessons in sequence.
Once you complete all five lessons, you will be ready to move on to the next chapter of Class 1 Mathematics.