Video Transcript
Ordering Numbers up to 20
In this video, we will learn how to
order numbers up to 20 by breaking them into tens and ones or by thinking about the
counting sequence.
The children from gardening club
have been growing chili plants. They want to know which plant
produced the most fruit. That means the most chilies. It looks like this plant produced
the least chilies. Let’s count them and see how many
there are. One, two, three, four, five, six,
seven, eight, nine. So this plant produced nine
chilies. This plant looks like it has more
than nine chilies. Let’s count them. Here are nine chilies, and we can
see there are still some more, so we need to keep on counting. We already know that this plant has
more than nine chilies. One more makes 10, 11, 12, 13, 14,
15, 16. Did you notice how we’ve arranged
the chilies? There’s a row of 10 and six
more. 10 and six makes 16.
Let’s count the last group of
chilies in the same way. We can make a group of 10 and some
ones. Do you know how many chilies this
plant produced? There’s a row of 10 and some
ones. How many ones can you see? There are two. 10, 11, 12. A 10 and two ones makes the number
12. Now we know how many chilies were
produced by each plant. Let’s order them from least to
greatest. The plant which produced the least
amount of chilies is the one which produced nine chilies, followed by the plant
which produced 12 chilies, and the plant which produced the most produced 16
chilies.
When we’re comparing and ordering
numbers, it sometimes helps if we group them into tens and ones. The number nine doesn’t have any
tens. It just has nine ones. A group of 12 chilies is made from
a row of 10 and two ones, and a group of 16 chilies is made from a row of 10 and six
ones. And this way we can see that the
greatest number is the number 16. Another way we could compare and
order these three numbers is to use the counting sequence. One, two, three, four, five, six,
seven, eight, nine, 10, 11, 12, 13, 14, 15, 16. Number nine comes first in the
counting sequence. This means that this is the
smallest number. And the number 16 comes last, so we
know that this is the greatest number.
So far in this video, we’ve learned
that we can compare and order numbers by grouping or arranging the numbers into tens
and ones and then comparing the number of tens and ones. And we’ve also learned that we can
compare and order numbers using the counting sequence. Let’s put into practice what we’ve
learned now by answering some questions.
Each group of animals has a pack of
10 and some loose members. Order the animals by how many are
in each group. Start with the smallest number.
In this question, we’re shown three
different groups of animals, a group of monkeys, a group of horses, and a group of
cats. The animals have been grouped into
a pack of 10 and some loose members. We have to order the animals by how
many are in each group, and we have to start with the smallest number. Let’s start by counting the
monkeys. We already know there’s a pack of
10 which have been circled and some loose members. Let’s count the number of monkeys
outside the circle. There are two. 10 and two more makes 12.
Let’s count the horses. We’ve got a group of 10 inside the
circle and some loose horses. How many horses are outside the
circle? There are six. 10 and six makes 16. Now let’s count the cats. We’ve got 10 cats inside the circle
and three outside the circle. 10 and three makes the number
13. Which of these is the smallest
number? 12, 16, or 13? To help us work out which is the
smallest number, we could use this number line. 10, 11, 12, 13, 14, 15, 16. We can see that the number 12 comes
first in the counting sequence, which means it’s the smallest number, followed by
the number 13. And the biggest number, the number
which comes last in the counting sequence, is number 16. 10 and two ones is less than 10 and
three ones and less than 10 and six ones.
We have to order the animals by how
many are in each group. The group with the smallest number
is the monkeys. There are 12 monkeys. The group with the most animals is
the one with horses. There are 16 horses. And there are 13 cats, which is
more than the number of monkeys and less than the number of horses. So the correct order of the animals
according to how many are in each group is monkeys, cats, and horses. We ordered the animals from the
smallest number to the greatest number. We used our knowledge of tens and
ones and the counting sequence to help. The correct order of the animals is
monkey, cat, horse.
Look at these numbers. 15, 11, 18. Which is the greatest number? Which is the smallest number?
In this question, we have to
compare three numbers, the numbers 15, 11, and 18. And we can see that each of these
numbers has been modeled using ten frames. We have to compare the numbers to
find the greatest number and the smallest. Let’s use these part–whole models
to help us compare the numbers. We can see from the model that the
number 15 is made up of a ten frame or 10 counters and five more. 10 and five makes the number
15. The number 11 is modeled using a
ten frame, which is full of 10 counters, and one more. 10 and one makes 11. And the number 18 has been modeled
using 10 and eight more. 10 and eight makes 18.
So if all of our numbers have a 10,
we just need to compare the ones. Five, one, and eight. Which of these three numbers is the
greatest? We know that eight is more than
five and more than one. So, that means that 10 and eight is
worth more than 10 and five and 10 and one. So the greatest number is the
number 18. Which of our two remaining numbers
is the smallest? Is it 15 or 11? We know that one is worth less than
five, so the smallest number must be number 11. 10 and one is less than 10 and
five. The smallest number is number
11. The greatest number is 18. The smallest number is 11.
Order the following numbers,
starting with the greatest number. 17, 16, eight, 14.
In this question, we have to
compare four numbers, and we can see that each of these numbers has been modeled
using blocks. Our first number, number 17, has
been modeled using a tens block and seven more. The number 16 has been modeled
using a tens block and six more. The number eight has been modeled
using a cube train with eight blocks. And the number 14 has been modeled
using a 10 and four more. We have to order the numbers,
starting with the greatest. The smallest number is number
eight. All of the other numbers have a 10
and some more, so we know the smallest number is number eight.
Which number should come first,
which is the greatest number? This is number 17. 10 and seven more is greater than
10 and six more and greater than 10 and four more. The greatest number is 17, and the
smallest number is number eight. We know that 16 is greater than 14
because 10 and six is more than 10 and four, and the number which comes between 16
and eight is 14. The correct order, starting with
the greatest number, is 17, 16, 14, eight. We compared the numbers using the
models we’ve been given and ordered them starting with the greatest number. The correct order is 17, 16, 14,
eight.
Order the following numbers,
starting with the smallest number: 15, 16, 11, 18, 13.
In this question, we have to order
the numbers we’re shown from smallest to largest. We have to compare our five
numbers. Let’s use a number line to
help. Let’s mark each of our numbers in
the correct place on the number line. 15, 16, 11, 18, and 13. So the smallest number is number
11. It comes first in the counting
sequence. The next number on the number line
is number 13, followed by number 15, number 16, and number 18. We ordered the numbers starting
from the smallest. We used the number line to
help. The correct order is 11, 13, 15,
16, 18.
What have we learned in this
video? We have learned how to order
numbers up to 20 by breaking them into tens and ones or by using the counting
sequence.
