Add within 20
Quick, comfortable adding is one of the first big wins in your child's math life. Sums like 8 + 6 turn up inside adding 28 + 6 next year and inside multiplying in 3rd grade. And once they come easily, your child's attention is free for the new idea in a problem. You'll see it in board games, at snack time, and whenever someone asks how many there are in all.
In this video, your child will learn to add using a ten or a double.
The lesson stops at each question for your child's answer.
Three problems, each a little harder
Each problem is worked step by step. Your child will solve the last one before Bobby shows how.
Example 1
9 + 4 = ?
Example 2
6 + 7 = ?
Your child's turn
7 + 5 = ?
The three key steps
- 1Make a ten first; split the other number to fill it.
- 2Then add what's left to ten.
- 3Or use a double you know, and one more.
Mistakes to listen for
- Counting by ones for every sum, which works for 3 + 2 but gets slow and error-prone for 9 + 7.
- Splitting a number wrongly when making ten, turning 8 + 5 into 8 + 2 + 2 and getting 12 instead of 13.
- Adjusting a double the wrong way, so 7 + 8, thought of as 8 + 8 = 16, comes out as 17 instead of 15.
The lesson shows every step, so your child sees why it works. Read our parent's guide to adding within 20 →
Is your child ready to practice what they've learned?
Bobby's Math Club offers unlimited practice for free.
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More 1st grade Problem Solving, with questions your child answers along the way.
Questions parents ask
Does my child need an account to watch?
No. You can watch this on any device at any time. If your child would like to practice adding within 20, and you'd like parent-friendly reports on your child's progress and growth, you can join Bobby's Math Club for unlimited free practice.
What happens when my child answers a question?
A right answer gets a cheer, and the lesson carries on. If your child isn't sure, they can tap "I don't know yet", and Bobby gives the answer and shows another example. Nothing is scored or stored.
Is this the same lesson that's on YouTube?
Yes. Here, the lesson stops at each question and waits for your child to answer. On YouTube, each question stays on screen for a few seconds, and then the lesson plays on.
Where can I learn more?
There's a short, kid-friendly lesson like this one for every Pre-K to 5th grade math skill, all in our video library. Our parent's guide to adding within 20 has more on where kids get stuck and how you can help at home. In the club, your child practices at just the right level, about five minutes a day, and you get parent-friendly reports as they grow. Learn more about how it works →
Practice adding within 20
Questions at your child's level, about five minutes a day, on adding within 20 and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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