Video Transcript
Arrange in descending order. 2700 kilograms; 5450 kilograms;
840000 grams; three and a quarter metric tons.
When we’re answering a question
like this, it might be very easy to look at the numerical values and simply try and
order these. The important thing to notice here,
however, is that the units of the mass are different. We have, in fact, got three types:
kilograms, grams, and metric tons. Note that the metric tons here is
also known as tonnes spelt with an extra n and e in different parts of the
world. We can only order these masses
whenever all the units are the same. If we were to order our three units
in terms of descending size, we’d have tons as the largest, then kilograms, and then
grams as the smallest. By that we mean that one ton is
bigger than one kilogram, and one kilogram is bigger than one gram.
When it comes to writing these in
the same units, we could choose any of the units of tons, kilograms, or grams to
write each value in. However, here we already have two
given in kilograms, so it might seem sensible to change all of these masses into a
value in kilograms. So how do we change a value in tons
into a value in kilograms? We can recall that one metric ton
is equal to 1000 kilograms. We could then say that to change a
value in tons into kilograms, we would multiply by 1000. So if we have three and one-quarter
tons, we could begin by writing this as 3.25 tons. And that’s because a quarter as a
decimal is 0.25.
To work out this value in
kilograms, we have 3.25 multiplied by 1000. When we’re multiplying by 1000, we
move all of our decimal digits three places to the left, giving us 3250
kilograms. As a check that our value is
roughly correct, if we imagine that we just had three tons, when we multiply three
by 1000, we’ll have 3000. So 3250 kilograms here would be in
the correct order of magnitude. Next on our list of masses, we need
to change 840000 grams into a value in kilograms. The conversion we need here is that
in one kilogram, there’s 1000 grams. So when we start with a value in
grams, we must actually divide by 1000 in order to get the equivalent in
kilograms. So 840000 grams is equal to 84,000
divided by 1000 kilograms, which we can write as 840 kilograms.
And now we have all four masses as
a value in kilograms. To arrange in descending order
means that we start with the largest mass first. So that will be 5450 kilograms. The next largest will be 3250
kilograms. But we must write that in the
original way it was given, as three and a quarter metric tons. Next, it’s 2700 kilograms. And finally, the smallest value of
840 kilograms, which we write in the original format of 840000 grams. And that’s our list of masses given
in descending order.
