# Lesson Video: Equality in Addition and Subtraction Number Sentences Mathematics • 1st Grade

In this video, we will learn how to verify and complete equations and understand the meaning of the equal sign

03:29

### 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.