Compare two lengths
Lining up two pencils to see which is longer is your child's first real taste of measuring. Getting the ends even is the habit they need in 1st grade, when they measure with paper clips or cubes, and in 2nd grade with a ruler, since a crooked start gives a wrong answer even when the counting is right. It also helps with everyday questions, like whether a couch will fit.
In this video, your child will learn to tell which thing is longer or shorter.
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
Which pencil is longer?
Example 2
Which one is taller: the pencil or the crayon?
Your child's turn
Which straw is shorter?
The three key steps
- 1Line up the ends.
- 2The one that goes farther is longer, or taller.
- 3The other one is shorter.
Mistakes to listen for
- Comparing two pencils without lining up their ends, so the one sticking out further looks longer.
- Calling one child taller while they stand on tiptoe or on a step, instead of on the same floor.
- Describing the difference only as "big," instead of saying taller, longer, or heavier.
The lesson shows every step, so your child sees why it works. Read our parent's guide to comparing which is longer, taller, or heavier →
Is your child ready to practice what they've learned?
Bobby's Math Club offers unlimited practice for free.
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More Kindergarten 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 comparing which is longer, taller, or heavier, 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 comparing which is longer, taller, or heavier 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 comparing which is longer, taller, or heavier
Questions at your child's level, about five minutes a day, on comparing which is longer, taller, or heavier and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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