Video Transcript
The flowers in a garden are in
three rows and seven columns. How many flowers are in the
garden?
Let’s start by highlighting the
important information that we can see in this problem. Now, we’re given a description of
how a group of flowers is arranged. We’re told that it’s laid out in
three rows and seven columns. And the question then goes on to
ask us how many flowers are there in the garden. Can you visualize the shape that
the flowers will make if they’re set out in rows and columns?
When a number can be arranged in
equal rows and columns, it usually makes it a rectangle, sometimes a square, and we
call it an array. And arrays are really useful ways
to represent multiplication facts visually and to help us understand them and to
help us solve problems like this. Let’s sketch the array in the
question using the information that we’ve been given.
So the flowers are in three
rows. So there are three rows. But how many flowers are in each
row? What we’re also told, that there
are seven columns. And this means that we know that
there must be seven flowers in each row. Let’s draw the seven columns to
show this. So there are our seven columns. So we can see that we have three
lots of seven. Or, if we said it a different way,
there are seven lots of three. So how can we use our array to find
the total amount?
Well, as we’ve seen, we can think
of the array in two different ways. Firstly, as seven lots of
three. So we can think of that as the
multiple addition: three plus three plus three plus three plus three plus three plus
three. That’s adding three seven
times. Or, we can simply write it as a
multiplication, seven multiplied by three. The second way to think of our
array is as three lots of seven, three rows of seven. And again, we can write this as a
multiple addition: seven plus seven plus seven. Or, we can simply use a
multiplication fact, three multiplied by seven.
All of these four calculations give
us the same answer. Let’s use the final one to find out
the total. We’ll count in sevens three
times. One times seven is seven. Two times seven is 14. And three times seven is 21. And so, by drawing the array of
three rows and seven columns, it really helped us to visualize the total and to find
the answer quickly. And so, there are 21 flowers in the
garden.
