Video Transcript
Find 28 divided by seven using the
cubes shown.
This question tests whether we know
how to divide by seven, and we’re told how to find the answer. We need to use the cubes that are
shown. Now these cubes, and there are 28
of them, aren’t just set out any way. They’ve been laid out in an
array. And we can use arrays like this to
help us solve division problems. Let’s think for a moment about what
dividing by seven means. We can think of the division in two
different ways, and we can use the array to show these two ways. Firstly, we can think of our
calculation as 28 shared into seven equal groups. Can you see a way to share our
array into seven equal groups? If we look closely, we can see that
there are seven columns in our array. So we could think of each column as
being one of our seven equal groups. And the answer to our division is
going to be the number of cubes in each group. Can you see how many there are?
If we share 28 cubes into seven
equal groups, there’ll be four cubes in each group. 28 divided by seven equals
four. But you know, we can use our array
to find the answer a different way. We can think of it as 28 grouped
into sevens. And once again, we can use our
array to help us. As we’ve seen already, our array
has seven columns, but we could think of this fact a different way. If we concentrate on the rows and
not the columns, we can say that each row contains seven cubes. So we can see that there are one,
two, three, four groups of seven.
This time, we know the number in
each group, but our answer tells us the number of sevens there are in 28. We found the answer to 28 divided
by seven by using the array. And we’ve shown that we can think
of this division in two different ways but still get the same answer. If we share 28 into seven equal
groups, there’ll be four cubes in each group. Or if we group 28 into sevens,
there’ll be four equal groups. 28 divided by seven equals
four.