Estimate lengths
Knowing roughly how long an inch, a foot, or a meter is gives your child a built-in way to check their own work, such as noticing that a pencil cannot be 7 feet long. Estimating is also something adults do constantly, from hanging a picture to judging whether a couch will fit through a door. In 3rd grade, the same habit carries over to estimating liquid volume and weight.
In this video, your child will learn to estimate how long something is.
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
About how many inches long is the crayon?
Example 2
A door is about 2 ___ tall. Which unit makes sense?
Your child's turn
A crayon is about 8 ___ long. Which unit makes sense?
The three key steps
- 1Picture a length you know.
- 2See about how many fit.
- 3"About", in a unit that fits.
Mistakes to listen for
- Guessing wildly, such as a 50-inch pencil or a 3-centimeter classroom, because the units have no meaning yet.
- Mixing up which unit is bigger, thinking a centimeter is longer than an inch or a foot longer than a meter.
- Treating an estimate as wrong unless it matches the measurement exactly, then not wanting to guess at all.
The lesson shows every step, so your child sees why it works. Read our parent's guide to estimating lengths in inches, feet, and meters →
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 estimating lengths in inches, feet, and meters, 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 estimating lengths in inches, feet, and meters 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 estimating lengths in inches, feet, and meters
Questions at your child's level, about five minutes a day, on estimating lengths in inches, feet, and meters and whatever PK-5 skills they need to develop. Unlimited practice, free forever.
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