Add and subtract on a number line
The number line is a picture your child will lean on for years. It makes mental strategies visible, such as jumping from 38 to 40 and then on to 65, and in 3rd grade it is where they learn that fractions like 1/2 and 3/4 are numbers that sit between whole numbers. Later still, it helps with rounding, negative numbers, and graphs.
In this video, your child will learn to add and subtract on a number line.
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
How far is it from 20 to 50?
Example 2
64 − 27 = ?
Your child's turn
46 + 27 = ?
The three key steps
- 1A number is a length from 0.
- 2Add? Jump forward.
- 3Subtract? Jump back.
Mistakes to listen for
- Counting marks instead of jumps, including the starting number, so 35 + 6 lands on 40 instead of 41.
- Spacing the marks unevenly, so distances look wrong and equal jumps appear different sizes.
- Moving the wrong way, jumping right to subtract or left to add, especially on unlabeled lines.
The lesson shows every step, so your child sees why it works. Read our parent's guide to adding and subtracting on a number line →
Is your child ready to practice what they've learned?
Bobby's Math Club offers unlimited practice for free.
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More 2nd grade Measurement & Data, 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 and subtracting on a number line, 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 and subtracting on a number line 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 and subtracting on a number line
Questions at your child's level, about five minutes a day, on adding and subtracting on a number line and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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