Video Transcript
True or False: If we measure
the mass of lighter objects, it is better to use kilograms than grams.
When we measure the mass of an
object, we’re trying to find out how heavy it is. And in our question, we can see
two units of measurement that we can use to weigh objects. Can you see them? There’s kilograms, which we
often write kg, and grams, for which we often write g. Now, we could use these units
of measurement to weigh anything, but it’s not always a good idea. Sometimes it’s better to use
one unit of measurement than the other. And this question is asking us
about lighter objects. If we’re measuring the mass of
lighter objects, is it better to use kilograms or grams?
What do you think we mean by
lighter objects? A feather is a light
object. This pen is a light object. You could probably say a carrot
is a light object too. It’s not heavy, is it? If an object is light, it’s not
heavy. Now, if we wanted to measure
the mass of these light objects, is it better to use kilograms or grams? To help us understand, we need
to remind ourselves how heavy one kilogram and one gram are. One kilogram weighs about the
same as a bag of rice. And one gram weighs about the
same as the lid of a ballpoint pen.
Now, which unit of measurement
do you think it makes sense to measure these light objects with? Would you weigh how heavy they
are in bags of rice or in pen lids? If we had a set of scales, we
put a bag of rice on one end and one of our light objects on the other, it would
come crashing down. A kilogram is much heavier than
our light objects. It would be much easier to see
how many pen lids weighed the same as a carrot. Grams are generally better for
weighing lighter objects and kilograms for weighing heavier objects.
Now, our sentence says, if we
measure the mass of lighter objects, it’s better to use kilograms than
grams. Well, we’ve just said this
isn’t true, is it? The statement is false. Let’s say it the correct way
round just to end with. If we measure the mass of
lighter objects, it is better to use grams than kilograms.
