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Math · Kindergarten Math

Chapter 1: Counting to Twenty

Sixteen to Twenty

All the way to twenty.

Lesson
3
Time
About 12 minutes
Practice sheets
0 of 16 done
Part 1 of 7Let's Learn

Step 1: Let's Learn

Read it, or press Listen and follow the words.

Watch the idea first — 53 seconds. Then read on, and try it yourself in the next step.

Sixteen, seventeen, eighteen, nineteen, twenty. The last of the teen numbers.

Listen for the number

4 more would make 20.

One full frame is ten. Count what is in the second frame. Six. Ten and six. Say it: six-teen. The six is in the name.

You can hear the number

Sixteen has six in it. Seventeen has seven. Once you notice that, you do not have to memorize them separately.

Step 2: Try It Yourself

Tap and try it out.

Fill both frames all the way. That is twenty.

How many18

2 more would make 20.

Sixteen to twenty. Move one step at a time.

Step 3: In Real Life

A box of crayons

A big crayon box holds twenty. Count them back in. Sixteen, seventeen, eighteen, nineteen, twenty. None are missing.

Step 4: Watch an Example

One step at a time.

Watch Mia Fill Both Frames

Mia counts to twenty with counters.

  1. Step 1

    She fills the first frame: ten.

    That is a full ten!

    Counters10

Watch Leo Count to Nineteen

Leo has counters in two frames. Leo starts. You finish.

  1. Step 1

    Leo sees the first frame is full. That is ten.

    That is a full ten!

    Counters10

Step 5: Your Turn

Practice makes it stick.

The Beads

Problem 1 of 13

Beads on a string. How many beads?

The Egg Boxes

Problem 2 of 13

Mia has two egg boxes. One is full. It holds ten. The other has six. How many eggs?

Full box
Other box
eggs

Up to Twenty

Say the counting words up to twenty.

Problem 3 of 13

What comes after fifteen?

Problem 4 of 13

What comes after eighteen?

Problem 5 of 13

What comes after nineteen?

Problem 6 of 13

Ten and ten is?

Find the Mistake

A friend counted. Can you spot the slip?

Problem 7 of 13

Sam counts these counters. He says 16. What did Sam do?

Problem 8 of 13

How many counters are there?

counters

Problem 9 of 13

Ana counts these counters. She says 6. What did Ana do?

Problem 10 of 13

How many counters are there?

counters

Which Way?

Pick the quicker way.

Problem 11 of 13

The first frame is full. Which way is quicker?

Problem 12 of 13

Are there twenty? Which way is quicker to check?

Make Eighteen

Fill the boxes.

Problem 13 of 13

Fill eighteen boxes.

Tap the boxes.

How many0

Step 6: Quick Check

Show what you know.

Question 1 of 1

Ten and eight more is?

Ready for more?Optional. Past the lesson, for anyone who wants it.

Stretch 1 of 1

No frames this time. How many stars?

stars

What You Learned

  • Sixteen through twenty finish the teens.
  • You can hear the number inside sixteen and seventeen.
  • Twenty is two full ten frames.
For the grown-up

Six-teen is six and ten. The word itself is telling you how it is built.

Two tens make twenty. Both frames completely full, nothing spilling over.

After twenty comes twenty-one, twenty-two. The ones repeat, with a new ten in front. That pattern never stops.