Unit 4 — Place Value to 1,000

Welcome to Grade 2 Mathematics!

Numbers help us describe the world around us.

We count people, measure distance, tell time, and solve problems using numbers.

Today we will learn how larger numbers are organized.

Understanding place value makes every future math lesson easier.

Digits and Place Value

Our number system uses ten digits:

• 0
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9

The value of a digit depends on its position.

This is called place value.

Ones, Tens, and Hundreds

Every whole number is made from places.

For example:

345

has:

• 3 hundreds
• 4 tens
• 5 ones

We can write it as:

300 + 40 + 5

Understanding place value helps us read and compare numbers.

Reading Larger Numbers

Let's look at another number.

582

We read it as:

five hundred eighty-two

It contains:

• 5 hundreds
• 8 tens
• 2 ones

Every digit has a different value because of where it is placed.

Comparing Numbers

Sometimes we need to know which number is greater.

Compare:

452

and

425

Both have 4 hundreds.

Now compare the tens.

5 tens is greater than 2 tens.

So:

452 > 425

Always compare from the largest place value first.

Even and Odd Numbers

Some numbers are even.

Some are odd.

Even numbers can be divided into two equal groups.

Examples:

• 20
• 42
• 118

Odd numbers leave one left over.

Examples:

• 15
• 37
• 201

Look at the ones digit to decide whether a number is even or odd.

Skip Counting

Skip counting helps us discover patterns.

Practice counting by:

• 2s
• 5s
• 10s
• 100s

Examples:

2, 4, 6, 8, 10...

5, 10, 15, 20...

10, 20, 30, 40...

100, 200, 300, 400...

Skip counting prepares us for multiplication.

Activity

Write five three-digit numbers.

For each number:

• circle the hundreds digit
• underline the tens digit
• box the ones digit

Then write each number in expanded form.

Example:

624

600 + 20 + 4

Practice

Answer these questions.

What is the value of the 7 in 742?

Write 538 in expanded form.

Which number is greater?

681 or 618

Is 296 even or odd?

Skip count by tens from 320 to 400.

Review

Today you learned:

• digits have different values depending on their position
• numbers can be written in expanded form
• place value helps compare numbers
• numbers may be even or odd
• skip counting reveals patterns

A strong understanding of place value is the foundation for all future mathematics.

Looking Ahead

Next we will learn faster ways to add and subtract larger numbers.

Place value will help us solve these problems accurately and confidently.