2nd Grade Math
Place Value
Unit 3
What is Place Value?
Place Value is the value of each digit in a number. In this unit we are going to focus on the ones, tens, the hundreds place value.
138
Base Ten Number System
When we write out numbers, we are using the base ten number system. For example when we write 138 (three hundred and twenty-four). We are saying that we have 1 set of 100, 3 sets of 10 and 8 sets of 1.
Watch this video to get a preview on place value!
We can use base ten blocks to represent numbers
The Ones Block: This block looks like one tiny cube. A ones block represents the number 1.
The Tens Block: This block looks like a long stick. A tens block represents the number 10.
The Hundreds Block: This block looks like a large square. A hundreds block represents the number 100.
Do you see any connections between these blocks?
I know I do!! Notice how the tens block has ten tiny segments. It takes 10 ones cubes to create 1 tens stick. Notice how the hundreds block has 100 tiny little squares, or it has 10 tens sticks.
Big Takeaways:
A tens block is made up of 10 ones cubes
A hundreds block is made up of 10 tens blocks, or 100 ones cubes
Let's Practice Together!
What number does this set of blocks represent?
Let's make some observations:
We have 1 tens rod and 7 ones cubes
The tens rod is worth 10
The ones cube is worth 1
1 tens rod (10) + 7 ones cubes (7) = 17
What number does this set of blocks represent?
Let's make some observations:
We have 2 tens rods and 5 ones cubes
Remember..... a tens rod = 10 and a ones cube =1
2 tens rods = 10 +10= 20
5 ones cubes = 1+1+1+1+1=5
20+5= 25
What is different about this model?
There are are hundreds blocks included. What number does this model represent?
Let's make some observations:
We have 2 hundreds blocks, 5 tens rods, and 6 ones cubes
Remember.... hundreds blocks = 100, tends rods = 10, and ones cubes = 6
2 hundreds (100+100= 200), 5 tends (10+10_10+10+10=50), 6 ones (1+1+1+1+1+1 =6)
200+50+6= 256
Worksheet Time:
Directions:
Write the number the blocks represent
Check your answers by scrolling down to the next page
Link: https://www.mathworksheets4kids.com/blocks/hundreds-tens-ones-1.pdf
Place Value? Why does placement matter?
8
What number do you think of when you see the number above? You probably think of the number 8.
80
What number do you think of when you see the number above? You probably think of the number 80.
Notice how the only difference between these two numbers is where the number 8 is placed. In our first example, the 8 is in the ones place. In our second example, the 8 is in the tens place.
The number 8 is represented by 8 ones cubes
The number 80 is represented by 8 tens cubes
Watch this video to learn more about place value!
Expanded Form
What is expanded form? Expanded form is a way of writing numbers to see the math value of individual digits. We can write in expanded form by using place value.
Watch this video to get a preview of expanded form
Example: 134
Let's look at our place values
In the ones place we have a 4 (1+1+1+1= 4)
In the tens place we have a 3 (10+ 10+10= 30)
In the hundreds place we have a 1 (100)
Expanded Form: 100 + 30+ 4
Example: 568
Let's look at out place values
In the ones place we have a 8 (1+1+1+1+1+1+1+1 =8)
In the tens place we have a 6 (10+ 10+10+10+10+10= 60)
In the hundreds place we have a 5 (100+ 100+ 100+ 100+ 100= 500)
500+60+8 = 568
