Video Transcript
Skip Counting with Arrays
In this video, we will learn how to
make arrays with up to five rows or columns and use skip counting and addition to
find the total number of objects in an array.
An arrangement of objects or
pictures in rows or columns is called an array. We could group these soldiers into
two rows. Each of these rows contains five
soldiers. To find the total number of
soldiers in this array, we could add together the two rows of five. We know that five plus five equals
10. So, we could say two rows of five
is 10.
An array is a group of objects
grouped together in either rows or columns. This array has five columns, and
each column contains two soldiers. We could find the total number of
soldiers by adding together our five groups or five columns of two. In other words, we would need to
add two plus two plus two plus two plus two. Two plus two is four. Four plus two is six. Six plus two is eight. And eight plus two is 10.
Another way we can find the total
number of soldiers in this array is to skip count by two. Two, four, six, eight, 10. Let’s try some example questions to
help us practice skip counting and adding to find the total number of objects in an
array.
An array can be used to model equal
groups of objects. Which of the following is not an
array?
We’re shown five different groups
of objects. One of these groups is not an
array, which means all the other groups are arrays. Which of these groups is not an
array? An array is when objects are
grouped together in equal rows, or columns. This is an array. This array shows three columns, and
each column contains three dots. This is an array. We can group the dots in the second
picture into three rows of two, so we know this picture is also an array.
This picture shows one row of four
dots. It’s an array. This picture shows three rows, but
the rows are not equal. The first row contains four dots,
but the second row only contains three, and the third row contains four dots. If the rows are not equal, this is
not an array. So, this is the model which is not
an array.
The cupcakes are in an array. How many rows are there? How many cupcakes are in each
row? How many cupcakes are in the
array?
We’re shown an array of
cupcakes. How many rows are there in the
array? There’s one row, two rows. Now, we need to work out how many
cupcakes there are in each row. One, two, three. How many cupcakes are there
altogether in the array? To find the total number of
cupcakes, we could add together the two rows of three. What is three plus three? The answer is six. Another way we could find the
answer is to skip count in threes. One three is three. Two threes make six. Three, six, we skip counted by
three. There are six cupcakes in the
array.
Madison is using skip counting to
count the number of fish. She sees that there are three fish
in each row, so she can skip count by threes. She says, three, six, what,
what. How many fish are there?
To find out the total number of
fish in the array, we need to skip count in threes. Madison started to skip count. Three, six. What comes next? Three, six, nine. Three, six, nine, 12. Four rows of three makes 12. Three, six, nine, 12. Madison found the answer by skip
counting.
What have we learned in this
video? We’ve learned that an array is a
group of objects arranged in rows or columns. And we can find the total number of
objects in an array by adding or skip counting.
