Video Transcript
Equality in Addition and
Subtraction Sentences
In this video, we’re going to learn
how to recognize if a number sentence is equal. Let’s look at an example.
True or false: three is equal to
six take away three.
We can read this number sentence as
three is equal to six take away three. The equal sign means that both
sides of this number sentence are equal. Let’s check if this is true. On this side of the equal sign, we
have three blocks; and on this side of the equal sign, we have six blocks, but we
need to take away three: one, two, three. Now we have three blocks in each
group. Is it true that three is equal to
three? Yes, it is. So the number sentence three is
equal to six minus three is true.
Let’s practice with another example
of a number sentence.
True or false: six is equal to two
plus three. On this side of the equal sign, we
have six. On this side of the equal sign, we
have two, and we need to add three more. So on this side, we have six
counters. And on this side, now we have five
counters. Six is not equal to five. Six is greater than five. So the number sentence six is equal
to two plus three is false.
Let’s practice with one more
example.
True or false: two is equal to
eight minus seven. On this side of the equal sign, we
have two. On this side, we have eight blocks,
but we need to take away seven: one, two, three, four, five, six, seven. Now we have two blocks on one side
and one block on the other. Is it true that two is equal to
one? No! The number sentence two is equal to
eight take away seven is false.
In this video, we’ve learnt how to
check if both sides of the equal sign in a number sentence are equal.
