Have students sing along with the ones, tens, hundreds song!
This video should help learners memorize the three units places.
Be sure to pause the video to count the base-ten blocks!

Start with the one’s place,
It's first in line,
Then 1 2 3 4 5 6 7 8
Next digit’s 9,
I get one more,
Now I got ten,
One in the ten’s place,
Let’s try it again…
Ones, tens, ones tens hundreds,
Ones, tens, ones tens hundreds,
Ones, tens, ones tens hundreds,
Every time!!

Started with the one’s place,
First in line,
Then,
1 2 3 4 5 6 7 8
Next digit’s 9...

Back to the ten’s place,
What’s to the left?
Let’s just count it,
To see what’s next!

10, 20, 30, 40,
50, 60, 70, 80,
90
What comes after 90?
I think I get 100...
10, 20, 30, 40,
50, 60, 70, 80,
90
What comes after 90?
I know it is 100

Ones, tens, ones tens hundreds,
Ones, tens, ones tens hundreds,
Ones, tens, ones tens hundreds,
Every time!
The hundred’s place,
It’s third in line,
You’ll always get there,
After 99!
The hundred’s place,
It’s third in line,
You’ll always get there,
After 99!