Turn tenths into hundredths to add them
Tenths and hundredths are your child's bridge from fractions to decimals, and money makes the link plain: a dime is a tenth of a dollar and a penny is a hundredth. Renaming 3/10 as 30/100 is what makes 0.3 and 0.30 the same amount, which they need when writing and comparing decimals this year. In 5th grade it grows into adding any fractions with different denominators.
In this video, your child will learn to turn tenths into hundredths and add.
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
3/10 = ?/100
Example 2
3/10 + 4/100 = ?
Your child's turn
6/10 + 25/100 = ?
The three key steps
- 11 tenth = 10 hundredths
- 2Turn the tenths into hundredths.
- 3Then add the hundredths.
Mistakes to listen for
- Adding tops and bottoms straight across, writing 3/10 + 4/100 = 7/110, without first renaming the tenths as hundredths.
- Renaming 3/10 as 3/100, changing the bottom to 100 but not multiplying the top by 10.
- Thinking 4/100 is larger than 3/10 because both of its numbers are bigger, not seeing that hundredths are tiny pieces.
The lesson shows every step, so your child sees why it works. Read our parent's guide to adding tenths and hundredths together →
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More 4th grade Numbers & Place Value, 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 tenths and hundredths together, 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 tenths and hundredths together 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 tenths and hundredths together
Questions at your child's level, about five minutes a day, on adding tenths and hundredths together and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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