*Contributor: Veronica Barna. Lesson ID: 10633*

Did you know that digits can play house? Or that the number 10 likes to hide inside other numbers? Digits stand next to each other in a certain order. You can "count" on learning why they do that!

categories

subject

Math

learning style

Kinesthetic, Visual

personality style

Otter, Golden Retriever

Grade Level

PreK/K, Primary (K-2)

Lesson Type

Quick Query

What do all of the colorful numbers in the picture below have in common?

Say each of the numbers out loud with your teacher or parent.

Take a moment to think about what you know about digits.

- How many digits does each of the above numbers have?

That’s right! Each of the numbers in the picture has 2 digits. You may also have said that most of the numbers end in the word *teen*.

- What else do you notice about the numbers?

Good job. You noticed that all of the numbers have the number "1" as the first digit! There is one more number that has the number 1 as the first digit.

- Do you know what that number is?

It's the number "10"! Ten has the number 1 as the first digit and a 0 as the second digit.

Let's take a minute to think about these numbers. They all have two digits, and they all have a 1 as the first digit. It seems like these numbers must have something special in common with the number 10.

**It's time to investigate**.

Let's begin by looking closely at one of these numbers:

Hmm ... It is the number seventeen, but there is something very suspicious about this picture.

- Do you think this picture of the number seventeen is strange?

If you agree, explain to your teacher or parent why.

Aha! *Ten* was behind this the whole time!

Ten never wanted to lose his *place value*, so he drops his zero and lets the ones add on in the ones place to create new numbers:

or

**Wait — What's place value?**

As you know, some numbers have just 1 digit while others can have up to 7 or 8 digits. You can probably count all the way to 100, which has three digits; but on the way up to 100, you pass 90 two-digit numbers. As you just saw in the example above, the number 17 has 1 ten and 7 ones. When you read a number from left to right, each digit has a special value. The number 10 has 1 ten and no ones.

- How many tens are in the number 14?

That's right, there is only 1.

- How many ones are in the number 14?

Great! There are 4 ones in the number 14.

As the numbers get larger, the digit in the place value gets larger, too. However, there can only ever be one digit in a place value holder at any given time.

A good way to think about place value is like rooms in a house. Take a few minutes to enjoy this Math & Learning Videos 4 Kids video about place value, and then you will start to practice placing things into rooms on your own.

*Place Value First Grade - Tens and Ones*:

**The House that Numbers Built**

In this house, the tens room is blue, and the ones room green. There are other rooms in the house, too. The hundreds room, which is before the tens room, can be orange. There is also a tenths room, which is in line AFTER the ones room, but we won't worry about that room today.

Let's use apples instead of blocks as our place holders in our rooms:

What number is represented in the house below?

There are no apples in the hundreds room. There is 1 bowl (which is the same as a 10 block) in the tens room.

- How many single apples are in the ones room? Right, 6.

Now, place your numbers together as shown in the video.

- What number is represented?

If you said 16, you are right!

Now, grab a pencil and paper and write the numbers represented by each house below. Ask your teacher or parent to check your answers when you are done:

Did you get them all correct?

Take a look at this next video to make sure you have a good understanding of place values before doing some house-building and place-valuing on your own! Sing along with this Mr. R.'s Songs for Teaching song, the *place value math song: ones, tens, hundreds*:

When you are rested from all your singing, move on to the *Got It?* section to sharpen your new skills!