Video Transcript
Comparing Numbers up to 20
In this video, we will learn how to
compare numbers up to 20 by breaking them into tens and ones or considering the
counting sequence. When we compare numbers, we use
these three symbols: less than, equal to, and greater than. A good way to remember what each of
these symbols means is to remember that we put the largest number at the largest end
of the symbol. Our two models show the numbers 14
and 18, and we can see that 14 is less than 18. Look what happens if we swap the
numbers around. We can use the greater than symbol
because 18 is greater than 14. 18 is worth more than 14. And if both of our ten frames
showed the number 14, we could say 14 is equal to 14.
These children have been helping to
clear up the balls after basketball. We can see the boy has collected 12
basketballs and the girl has collected 14. When the basketballs are grouped
like this, it’s hard to see which group has the most. Lining the basketballs up like this
makes it much easier to compare our two numbers. Each group has a row of 10
basketballs and some more. 10 and two more makes 12. 10 and four more makes 14. We know that four is more than two,
so 10 and four is more than 10 and two. Then if we look at this counting
strip, we can see the number 14 comes after number 12 in the counting sequence. This means that 14 is greater than
12.
Can you remember how to write this
using the symbol? This is the greater than
symbol. 14 is greater than 12. So we’ve learned that when we’re
comparing two numbers up to 20, we can break the number into tens and ones to help
us compare. And we can also use the counting
sequence. Let’s practice what we’ve learned
with some questions now.
Hannah planted 17 flowers. Amelia planted 19 flowers. Pick the correct symbol to compare
the number of flowers: equal to, greater than, or less than. Who planted less flowers?
In this question, we have to
compare the number of flowers planted by Hannah and the number of flowers planted by
Amelia. And we’re told that Hannah planted
17 flowers, whilst Amelia planted 19. We’re being asked to pick the
correct symbol to compare the number of flowers. In other words, is 17 equal to 19,
greater than 19, or less than 19? We could use the pictures to
help. The amount of flowers that Hannah
has has been broken apart into two groups, a 10 and seven more. We can break the number 17 apart
into one ten and seven ones.
Amilia’s flowers have also been
broken apart. She has a group of 10 flowers and a
group of nine flowers. If we break the number 19 apart, we
get one ten and nine ones. Nine is worth more than seven. We can see this just by looking at
the row of flowers. Seven is less than nine, so we need
to use the less than symbol. If seven is less than nine, then 17
is less than 19. The correct symbol to compare the
number of flowers is less than because 17 is less than 19. So who planted less flowers? Was it Hannah or Amelia? 17 is less than 19, and Hannah
planted 17 flowers, so Hannah planted less flowers.
Anthony is using ten frames to help
him compare numbers. Which is smaller, four or
seven? Which is smaller, 14 or 17? Pick the correct symbol to compare
the numbers. 14 is equal to 17, 14 is greater
than 17, or 14 is less than 17.
This question is all about
comparing numbers. Which number is smaller, four or
seven? Let’s use Anthony’s ten frames to
help us. This ten frame represents the
number four; it has four counters. And this ten frame represents the
number seven because it has seven counters. This ten frame has less than the
other and this ten frame has more. Four is less than seven. The ten frame with four counters
has less than the ten frame with seven counters, so four is smaller than seven.
Next, we have to compare the
numbers 14 and 17. Anthony has used two ten frames to
make the number 14. The first ten frame is full of
counters; it contains 10. And the second ten frame contains
four counters because 10 and four makes the number 14. Anthony has modeled the number 17
with a 10 and seven ones, and we already know that four is less than seven. We know that both of these numbers
have a 10, so we’re just comparing the ones. The number 14 is less than the
number 17, so the number which is smaller is 14. 10 and four ones is less than 10
and seven ones. Now what we need to do is answer
the last part of the question. Which symbol do we need to use to
compare the numbers 14 and 17? 14 is less than 17. Four is less than seven; 14 is less
than 17.
Scarlett is using base 10 blocks to
help her compare numbers. Which is bigger, eight or
three? Which is bigger, 18 or 13? Pick the correct symbol to compare
the numbers. 18 is less than 13, 18 is equal to
13, or 18 is greater than 13.
This question is all about
comparing numbers. First, we have to compare the
numbers eight and three and decide which is bigger. One way to compare the numbers
would be to look at the size of the group. We can see that eight squares is
more than three squares. The group with eight has more. The group with three has less. When we’re counting, the number
eight comes after the number three, three, four, five, six, seven, eight. We know when we’re counting
forwards, the numbers get bigger. Eight is bigger than three.
Now we have to compare the numbers
18 and 13. We can see the number 18 has been
broken apart into one ten and eight ones. 18 is 10 and eight ones. And the number 13 has been broken
apart into a 10 and three ones. We already know that eight is more
than three, so 10 and eight ones must be worth more than 10 and three ones. So the number which is bigger or
worth more is the number 18. The final part of this question
asks us to pick the correct symbol to compare the numbers 18 and 13.
This first symbol means less
than. 18 is not less than 13. It’s more than 13. We know this isn’t the correct
symbol, and this symbol means equal to. 18 is not equal to 13; it’s worth
more. So it must be this symbol, greater
than. The correct symbol to compare the
numbers is greater than because 18 is greater than 13.
What have we learned in this
video? We’ve learned how to compare two
numbers by breaking them apart into tens and ones. We’ve also learned how to use the
counting sequence to compare numbers.
