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International Baccalaureate · PYP 0

Comparing Capacities; Hotter or Colder

⌚ ~82 min ▢ 8 blocks ✓ 32 exercises ➣ Prerequisites : Comparing Lengths, Comparing Masses
I Full or Empty?

Mia pours water into a glass, little by little.
Figure
When must Mia stop pouring?

When the water reaches the brim, the top edge of the glass, the glass is full: Mia stops. If she keeps pouring, the water spills over the brim and runs down the glass.
Figure
The glass overflows.


Definition — Full and Empty
A container is empty when there is no water in it. It is full when the water reaches the brim: no more water can go in. If we pour more water into a full container, the water spills out: the container overflows.
Figure
Example
Which bucket is full? Which bucket is empty?
Figure

Figure
The bucket in the middle is full: the water reaches the brim. The bucket on the right is empty: there is no water in it. The bucket on the left is neither full nor empty.

Skills to practice
  • Finding Full and Empty
II Which Holds More?

Here are a bottle and a bowl.
Figure
Which one can hold more water? Our eyes cannot tell.

We fill the bottle to the brim. Then we pour all of its water into the empty bowl:
Figure
The bowl is not full: there is still room for more water. The bowl holds more than the bottle.


Definition — Holds More and Holds Less
When two containers are full, the one with more water in it holds more. The other one holds less. If they have just as much water, they hold the same.
Method — Pouring One into the Other
To compare two containers, we pour one into the other.
  1. We fill the first container to the brim.
  2. We pour all of its water into the second container, which is empty.
Then we look at the second container:
Figure
  • it overflows: the first container holds more;
  • it is not full: the second container holds more;
  • it is just full: the two containers hold the same.
Example
We fill the jug to the brim. We pour all of its water into the empty saucepan.
Figure
Which one holds more?

The saucepan overflows: not all the water of the jug fits in it. The jug holds more than the saucepan.

Skills to practice
  • Reading the Pouring
III Ordering Three Containers
Example
We pour twice. Each time, we fill the first container to the brim and pour all of its water into the second, empty one: the cup into the glass, then the glass into the jug.
Figure
Order the three containers from the one that holds the least to the one that holds the most.

The first pouring says: the glass holds more than the cup. The second pouring says: the jug holds more than the glass. So the order is cup, glass, jug, from the one that holds the least to the one that holds the most. We never poured the cup into the jug, but thinking tells us that the jug holds more than the cup.

Skills to practice
  • Finding the Most and the Least
  • Ordering Three Containers
IV Taller Does Not Always Mean More
The Taller One Does Not Always Hold More
The vase is much taller than the bowl. We fill the vase to the brim and pour all of its water into the empty bowl:
Figure
The bowl is not full: the bowl holds more, even though the vase is taller. The bowl is wide. Being tall and holding more are two different things: to know which one holds more, we pour.
Report an error
Skills to practice
  • Looking Past the Height
V Hotter or Colder?

Sam has two bowls of water. They look exactly the same.
Figure
Which bowl holds the warmer water? We cannot see it with our eyes.

Sam asks an adult, who checks that the water is not too hot. Then Sam dips a finger into each bowl. The water on the left feels warm, the water on the right feels cold: the left bowl holds the warmer water.
Figure
We find it out by touching, not by looking.


Definition — Hotter and Colder
Some things are hot, like soup just cooked. Some are cold, like snow. In between, some are warm, like bath water.
Figure
When we compare two things, the one that feels hotter is hotter; the other one is colder. If neither feels hotter, they are just as warm as each other.
Method — Feeling Which One Is Hotter
Hot and cold are felt, not seen. To compare two things:
  1. we first ask an adult: something very hot can burn, and we never touch it;
  2. we touch the first thing, then the second one, with the same hand;
  3. the one that feels hotter is the hotter one.
Figure
On an afternoon in the park, we touch one bench, then the other, with the same hand: the bench in the sun feels hotter than the bench in the shade.
A Picture Only Reminds Us
We cannot touch a picture. The steam above the soup and the frost on the ice lolly are only clues: they remind us of what we already know — soup just cooked is usually hot, an ice lolly is usually cold. Two things that look the same, like Sam's two bowls of water, can only be compared by touching them, once an adult says it is safe.
Figure
Report an error
Example
Order these three things from the coldest to the hottest.
Figure

The ice lolly is cold, the bath is warm, the cocoa is hot. From the coldest to the hottest: the ice lolly, the bath, the cocoa.
Figure

Skills to practice
  • Finding the Hotter One
  • Finding the Colder One
  • Ordering from the Coldest to the Hottest
VI Review & Quizz
Skills to practice
  • Quiz