Change bigger units into smaller units
Converting units is something your child will do all their life, like knowing that a 2-hour movie is 120 minutes or that a 3-foot shelf is 36 inches, and it helps them judge whether a measurement makes sense. Next year they convert in both directions, including inches back into feet, and use conversions in longer problems. In later science classes, moving smoothly between grams, liters, and meters becomes an everyday need.
In this video, your child will learn to change bigger units into smaller units.
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 kilograms = ? grams
Example 2
2 hours 15 minutes = ? minutes
Your child's turn
1 pound = 16 ounces. 4 pounds 5 ounces = ? ounces
The three key steps
- 11 big unit is many small units.
- 2Each one adds the same amount.
- 3Then add the extra small units.
Mistakes to listen for
- Dividing instead of multiplying when changing to a smaller unit, so 4 feet comes out as fewer than 4 inches.
- Assuming every unit works in tens, so 1 hour becomes 100 minutes or 1 pound becomes 10 ounces.
- Trying to convert feet straight into centimeters, when this year's work stays inside one system at a time.
The lesson shows every step, so your child sees why it works. Read our parent's guide to converting feet to inches and kilograms to grams →
Is your child ready to practice what they've learned?
Bobby's Math Club offers unlimited practice for free.
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More 4th 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 converting feet to inches and kilograms to grams, 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 converting feet to inches and kilograms to grams 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 converting feet to inches and kilograms to grams
Questions at your child's level, about five minutes a day, on converting feet to inches and kilograms to grams and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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