Water Balloon Capacity

Teacher: Good morning, Caleb! Look at what we’re working with today.

Student: No way! We get to play with water balloons at school?

Teacher: Yes! Today we’re going to measure the capacity of these water balloons. We’ll be working in the metric system, using liters and milliliters.

Student: What are liters and milliliters?

Teacher: Great question! Liters and milliliters measure capacity. A milliliter is about the size of a drop of water. A liter is about the size of a large water bottle. 1 liter is made up of 1,000 milliliters.

Student: That makes sense! 1,000 drops of water would fill a big water bottle.

Teacher: Exactly! Now, let’s fill these water balloons!

Teacher: This water balloon has 5 mL of water, and this water balloon has 500 mL of water. What do you notice about the balloons?

Student: The balloon with 5 mL of water is much smaller, and even though 500 is a big number, the balloon with 500 mL of water isn’t really that big.

Teacher: I agree! 500 mL is half of a liter. Let’s see what 1 liter of water looks like.

Student: Ah ha! Now that’s a full water balloon! What if we filled the water balloon with more than a liter?

Teacher: Let’s try it. I’ll fill this balloon with 2 liters of water. Remember, that’s the same amount as 2 large water bottles.

Student: Whoa! It popped!

Teacher: 2 liters was too much water for the capacity of this balloon.

Student: Let’s compare more measurements! Can I see 20 mL and 5 L?

Teacher: Sure! We’ll need a small balloon and a very large balloon. Let’s see… ah, here we go! 20 mL and 5 L.

Student: Wow! The 5 L balloon is HUGE! It’s even bigger than I thought it would be.

Teacher: I agree! What do you notice about the 20 mL balloon?

Student: Well, just like you said, it looks like it’s only filled with 20 drops of water, so it’s very small.

Teacher: Nicely done. Now, how about we go outside and throw these water balloons?

Student: Yahoo!

Teacher: You did a great job learning about liters and milliliters!