Convert Between Tens and Ones

Imagine you have this many blocks:

How many do you have? It takes a while to count them one at a time.

To make it easier, you can **group 10 blocks** into **one Tens** stack.

**10 Ones **are worth the same as **1 Tens.**

Now imagine you have 21 blocks. You can group them into 2 Tens and 1 Ones:

How many Tens does the number 21 have?

It has 2 Tens.

Imagine you have 21 blocks.

How many different ways can you make 21 using Tens and Ones?

Let's take a look:

- 2 Tens + 1 Ones = 21
- 1 Tens + 1 Tens + 1 Ones = 21
- 1 Tens + 11 Ones = 21
- 0 Tens + 21 Ones = 21

Wow! There are a bunch of ways. That's because you can always **break up 1 Tens into 10 Ones** if you need to.

Now you know how to **convert 10 Ones into 1 Tens and back**.

Great job! You've learned how to convert between Tens and Ones. Now try the practice below.

Teachers:

Effective, Personalized Learning on Any Device

Give each of your students their own profile with unlimited lessons, practice, and progress tracking.

Common Core Mastery for 1st - 4th Grade

Step-by-step adaptive lessons written to grade help students learn and retain more with less effort.

Student Analytics

Easily review student progress from the teacher profile.

Trusted by over 100k students, parents, and teachers each month.

Parent

Teacher

Up to 5 students

$39.99 / Year

$6.99 / Month$3.33 / Month

You save $43.89 with the annual plan

7 day free trial