### Video Transcript

Fill in the blank: The mass of the
box of books is what kilograms heavier than the mass of the box of toys. And then we’re given two sentences
to help us. The mass of the box of books is 31
kilograms. The mass of the box of toys is 25
kilograms.

In this question, we’re shown two
boxes. And we don’t need to weigh them to
find out how heavy they are because we’re told that the mass of the box of books is
31 kilograms and the mass of the box of toys is 25 kilograms. Now, we know that the number 31 is
a larger number than 25. And because both masses are
measured in kilograms, all we have to do to compare them is to just look at these
numbers. We know that the mass of the box of
books then is heavier than the mass of the box of toys. It weighs more. 31 kilograms is heavier than 25
kilograms.

Now, we’re given a sentence that we
need to complete. The mass of the box of books is
what kilograms heavier than the mass of the box of toys. In other words, we know that the
books weigh more. But how much more? Let’s count backwards from 31
kilograms to 25 kilograms to see. We could make a jump of one to go
from 31 back to 30. And then we know to go from 30 to
25 is a jump of five. So we’ve made a jump of one and
then a jump of five. How many kilograms is that? It’s six, isn’t it? The difference between 25 kilograms
and 31 kilograms is six kilograms. And so we can say the mass of the
box of books is six kilograms heavier than the mass of the box of toys. The missing number is six.