Video Transcript
Comparing Addition Sentences
In this video, we will learn how to
compare addition sentences with sums up to 10 by modeling and comparing the
parts.
We can use the symbols less than,
equal to, and greater than to compare numbers. Six is less than eight. Three is equal to three. Nine is greater than four. We can also use these symbols to
help us compare addition sentences. For example, one plus two is less
than two plus two. One counter and two more counters
makes three altogether. Two plus two is four. So, we can say that one plus two is
less than two plus two. We can tell that one plus two is
less than two plus two without even adding. These parts both contain two
counters. This part has one counter, but this
part has two. One is less than two. So, we know that one plus two is
less than two plus two. Let’s practice comparing addition
sentences.
We can compare numbers and
sums. Which is greater, seven or six?
We’re shown two different
part-whole models. The first shows the number seven,
and the second shows the number six. We have to work out which is
greater, seven or six? Let’s compare the parts. The first part, which makes seven,
contains two bricks. How many parts are in the second
part? Let’s count. One, two, three, four, five. Two plus five makes seven.
Let’s look at the parts which make
the number six. This part contains two bricks. It’s the same as this part, which
also has two bricks. One of the parts which make seven
plus one of the parts which make six are the same. Let’s count the bricks in the
second part to make six. One, two, three, four. Four and two make six.
Both numbers are made using a part
containing two blocks: two plus five and two plus four. Five is one more than four. Five is greater than four. So, we know that this part is worth
more than this part. The number which is greater is
number seven. Seven is greater than six.
Which is greater, two plus five or
four plus two?
We know that five is greater than
four and two is equal to two. Because five is greater than four,
we can say that two plus five is greater than four plus two. We didn’t need to add. We just needed to compare the size
of the parts. Two plus five is greater than four
plus two.
Pick the correct symbol to compare
the sums. Three plus two is equal to, less
than, or greater than one plus four. Hint: Make models and think about
the sums. Three and two is what? One and four is what?
We have to compare two sums or two
addition sentences, three plus two and one plus four. We have to pick the correct symbol
to compare them. It could be equal to, less than, or
greater than. We’re given a hint. We’re told to make models and think
about the sums. Our first part-whole model shows
two parts, three and two. This model shows the sum three plus
two, but we don’t know the total. Let’s use a model to help us find
the total. Let’s use a five frame and some
counters.
Three and two make five, and one
plus four also makes five. Both sums equal five. So, the correct symbol is equal
to. Three plus two is equal to one plus
four. Both sums give us a total of
five. So, the correct symbol to compare
the sums is the equal to symbol.
What have we learned in this
video? We found two ways to compare
addition sentences. We could compare the parts or find
the total using models.
