Place Value to 100
Learn how numbers are made up of tens and ones. Every number has a special place!
What Is Place Value?
Every number is made up of digits. The place of each digit tells us how much it is worth. In a two-digit number, we have tens and ones.
Think of it like building with blocks. A tens stick is worth 10, and a ones cube is worth 1.
Base-10 Blocks: The Number 34
3 Tens = 30
4 Ones = 4
Place Value Chart
| Tens | Ones |
|---|---|
| 3 | 4 |
The 3 is in the tens place (worth 30). The 4 is in the ones place (worth 4).
Partitioning Numbers
Partitioning means breaking a number into its tens and ones. It is like taking a number apart to see what is inside!
The number 56
5 tens and 6 ones
The number 82
8 tens and 2 ones
The number 47
4 tens and 7 ones
The number 100
10 tens make 100 - that is one hundred!
Key Vocabulary
Tens
Groups of 10. The tens digit tells us how many groups of 10 we have.
Ones
Single units. The ones digit tells us how many extra ones we have after the tens.
Partition
To break a number apart into tens and ones. For example, 63 = 60 + 3.
Place Value
The value of a digit based on where it sits in a number.
Worked Examples
How many tens and ones are in the number 72?
Step 1: The digit 7 is in the tens place. That means 7 tens = 70.
Step 2: The digit 2 is in the ones place. That means 2 ones = 2.
Answer: 72 has 7 tens and 2 ones. We can write 72 = 70 + 2.
What number has 5 tens and 9 ones?
Step 1: 5 tens = 50.
Step 2: 9 ones = 9.
Answer: 50 + 9 = 59.
Partition the number 46.
Step 1: Look at the tens digit: 4. That is 4 tens = 40.
Step 2: Look at the ones digit: 6. That is 6 ones = 6.
Answer: 46 = 40 + 6.
Knowledge Check
Pick the correct answer and press "Check Answer" to see how you did!
Question 1
How many tens are in the number 63?
Question 2
What number is made from 4 tens and 8 ones?
Question 3
Which partition is correct for the number 91?
Question 4
What is the ones digit in the number 57?
Question 5
Look at these base-10 blocks. What number do they show?
Key Concepts Summary
- ● Numbers are made of tens and ones.
- ● The tens digit tells us how many groups of 10 we have.
- ● The ones digit tells us how many single units we have.
- ● Partitioning breaks a number into tens and ones (e.g. 47 = 40 + 7).
- ● 10 tens make 100 (one hundred).