# Are you sure?

Are you sure your child has had sufficient hands-on practical activities at home to develop key ideas about capacity?

At the youngest level capacity means pouring liquid (or fluid materials such as sand or rice) from container to container. Great to do outdoors before the weather cools down! During such activities we can have conversations about:

• full, nearly full, empty, nearly empty, fuller, emptier, half full,
• holds more than/less than, same as,
• 4 eggcupfuls to fill this cup.

Attention can be drawn to the shape, height, width of containers and predictions of which will hold most. For example, beginning to notice that the tallest container may hold less than a short wide one.

Teachers cannot spend as much time one-on-one with a student to develop these ideas and understandings as you can. So help out here!

As children get older, they are supposed to know that capacity is measured in litres and millilitres and that there are 1000 mls in a litre, half a litre is 500 mls and they should be able to read the scale on measuring jugs.

In reality, many students have not had the practical, hands-on experiences with measuring capacity at home that is needed for them to notice where millilitres are used on a daily basis. They have no idea that the milk carton holds a litre or the juice container holds 2L. They have no idea how heavy a litre feels like and absolutely no idea about how small a millilitre is. Did you know a drop from a dropper is about a millilitre?

Put paper and pencil away today and investigate the capacity of containers in your home. Let your children feel how heavy a litre/half a litre actually is. Get out a dropper and see if a teaspoon actually holds 10 mls or if two half-cup measures of water actually fills a one cup measure.

Carry out investigations such as:

• How much water do you drink in a day?
• Does 2 litres feel like a lot of water to drink in a day?
• How many drops of cordial does it take to make 200mLs of water taste just the way you like it?
• How many cups of water does it take to fill a 1 litre container?

Most important share with your children all the ways that you use and think about capacity on a daily basis and as you carry out those things over the next few days, cooking, petrol in the car, mixing up fertilizer for the garden and so on. Remember teachers can’t do all of this stuff with the 20 plus students in their class in the same way as you can.

If students have the practical understanding teachers can develop the more abstract thinking.

Have fun, get messy today!