Some numbers are made of whole tens only. Nothing is left over.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
What the 0 means
In 30 the 0 does not mean nothing. It means no ones.
Counting tens sounds like counting: one ten, two tens, three tens.
The zero is doing a job
In 30 the zero says there are no loose ones. Without it you would write 3, which means something entirely different.
Zero holds the place open
It is not nothing. It is a marker that keeps the 3 in the tens column where it belongs.
Step 2: Try It Yourself
Tap and try it out.
Tens
2
Ones
0
2 tens and 0 ones is 20.
Step 3: Watch an Example
One step at a time.
Watch Ana Count Rods
Ana has four full rods and nothing else.
- Step 1
She counts the rods: one ten, two tens, three tens, four tens.
Step 4: Your Turn
Practice makes it stick.
Egg Boxes
Problem 1 of 1
Each box holds ten eggs. Leo has 3 full boxes. How many eggs?
eggs
Tens Only
1 of 3
How many tens are in 40?
2 of 3
Two tens is which number?
3 of 3
How many ones are in 30?
Step 5: Quick Check
Show what you know.
Question 1 of 2
Three tens is which number?
Question 2 of 2
What does the 0 in 20 mean?
What You Learned
- 10, 20, 30, and 40 are made of whole tens.
- They have zero ones.
- The 0 means no ones, not nothing.