Reading and Writing 11 and 12
In this video, we’re going to learn
how to read, write, and model the numbers 11 and 12. Now, what do we know about the
numbers 11 and 12? Well, the first thing we know is
where these two numbers belong. We know how to count to 10, don’t
we? One, two, three, four, five, six,
seven, eight, nine, 10. But what happens when we get to
10? The number that comes straight
after 10 is 11. 11 is one more than 10. So if we count to 10 and then count
one more, we’ve counted 11. And we can model the number 11 by
showing 10 and one more.
This 10 frame is full. So we know it shows the number
10. Now, our model shows one more than
10. We can see 11. Now, what about the number 12? The number 12 comes after the
number 11. So this is one, two more than
10. So we can model the number 12 by
showing 10 and two more. This string of beads is full, so we
know it shows 10. Now, we have two more than 10. 10, 11, 12. We’ve modeled the number 12 by
showing 10 and two more.
Another way of showing these
numbers is using digits. Have you noticed how we’ve used
digits to write these numbers already? Now, just like the number 10, the
numbers 11 and 12 both have two digits. We can call them two-digit
numbers. So we can use some of the digits we
already know to help us write 11 and 12. All you have to do to write the
number 11 is be able to write the digit one because the number 11 is a one followed
by another one.
So we can start at the top and draw
a line down and then start at the top again and draw another line straight down. Can you see this number on our
number track? It is the number 11, two ones
written side by side. When we write the number 12, we
start off with a one digit again. But this time, the second digit is
a two. So a one followed by a two gives us
the number 12. So we start at the top and draw a
line straight down for the digit one. And for the digit two, we start
about here and we draw a line that goes up and around down to the bottom and
straight across. A one followed by a two is the
number 12. And here’s our number 12 on the
number track. Can you see the two digits one and
two next to each other? So when we see these two numbers,
we know they mean 11 and 12.
Now that we know how to read these
numbers, how to write them in words, in digits, and also how to model one, we’re
ready to start practicing what we’ve learned. Let’s try answering some questions
now where we have to use our knowledge of 11 and 12.
Which set has 12 things?
In the picture, we can see three
sets of different things. One, two, three. And it looks like our sets are all
to do with space, doesn’t it? They all contain the Sun and lots
of planets. But how many space things are in
each set? We need to find the set that has
this number here. It’s a one followed by a two. Do you know how to say this
number? It’s the number 12.
Let’s count the objects in our
first set. Are there 12 things? One, two, three, four, five, six,
seven, eight, nine, 10. And with the Sun in the middle,
this is one more than 10. This set has 11 things. Remember, we’re looking for a set
that has 12 things. What about our second set? We can count one, two, three, four,
five, six, seven, eight, nine, 10. One more than 10 is 11. Two more than 10 is the number
we’re looking for, 12. But we’ve still gotta count the Sun
in the middle, haven’t we? This set contains more than 12
things. If you want to know the name for
this number, it’s 13. But we don’t need to worry about
this. All we need to know is that this
set doesn’t contain exactly 12 things.
So we’re only left with this last
set. Let’s hope there are exactly 12
things in this set. One, two, three, four, five, six,
seven, eight, nine, 10. And we know one more than 10 is 11
and two more than 10 is called 12. We counted the things in each set
to find the set that had 12 things. And this was the set that had two
more than 10.
Are there 11 pieces of candy in the
In the picture, we can see a bag
that contains a number of pieces of candy. But how many are there? We’re asked whether the bag
contains this number of pieces. Do you know how to read this
number? When we see a two-digit number like
this, there’s a one next door to another one, we know it’s the number 11. It’s the number after 10, isn’t
it? It’s one more than 10. Let’s put one plastic counter under
this 10 frame for every piece of candy that we can count. One, two, three, four, five, six,
seven, eight, nine, 10.
We can tell we’ve got 10 pieces of
candy because we’ve filled up our 10 frame. But we’ve still got one more piece
of candy to count. So we’re going to need to start a
new 10 frame. And as we’ve said already, the
number that comes after 10 is 11. One more than 10 is 11. And so when we’re asked, “Are there
11 pieces of candy in the bag?,” we need to say, “Yes, there are.” And we use 10 frames to show
Which of the following models
Underneath the question, we can see
some pictures of 10 frames. And you know 10 frames are a good
way of representing or showing numbers. But which of our models represents
or shows this number here? What is this number here? How would you say it?
When we see a one digit followed by
a two digit, we know it’s the number 12. Now, there are two ways we could
find the answer here. We could look at each of the models
one by one and count the number of counters. That way, we could see which one
has 12 counters.
But a quicker way to find the
answer is to use what we know about the number 12. Where does the number 12
belong? We know that the number 12 is two
more than 10. One, two, three, four, five, six,
seven, eight, nine, 10, 11, 12. Now, which of our models shows two
more than 10? Now, we know that a full 10 frame
shows the number 10. Here’s a full 10 frame. So this shows 10, and then one more
than 10. One, two, three, four, five, six,
seven, eight, nine, 10, 11. This model represents the number
11, not 12.
This model shows a full 10 frame
too. But how many more than 10 does it
show? One, two. One, two, three, four, five, six,
seven, eight, nine, 10, 11, 12. This is the model that represents
the number 12. And if we quickly look at the other
models, we can see two counters in the first one.
And now our last model only shows
the number one. We know that the number 12 is two
numbers after 10. And so the model that represents
the number 12 is the one that shows a full 10 frame or 10 and then two more. 12 is two more than 10.
What have we learned in this
video? We’ve learned how to read, write,
and model the numbers 11 and 12.