# Understanding Equals Sign and Addition and Subtraction Equations

Understanding what the equals sign means and how addition and subtraction equations work is a first grade, Common Core math skill: 1.OA.7.  Below we show two videos that demonstrate this standard. Then, we provide a breakdown of the specific steps in the videos to help you teach your class.

Prior Learnings

Your students should be familiar with comparing the number of objects within two groups to determine whether the groups are equal. They should also be able to compare two numbers (between 1 and 10) and decide if they are equal (K.CC.6-7).

Future Learnings

Later in the second grade, your students will be able to write equations that express equivalent groups and use even numbers, equal parts, skip counting, etc. (2.OA.3-4). They will also be able to write equations to solve word problems (2.OA.1).

Common Core Standard: 1.OA.7 - Understand the meaning of the equal sign and determine if equations involving addition and subtraction are true or false.

Students who understand this principle can:

1. Explain what equal means by using models and drawings.
2. Determine if two values are equal.
3. Represent equal quantities with operations on either side, neither side, or both sides of the equal sign.
4. Decide if an equation is true or false.

Video 2: See if Equations are True or False

The video offers 4 equations and checks to make sure each is true. The equations are as follows:

1. 6 = 6         ?
2. 5 + 2 = 7   ?
3. 10 - 4 = 7  ?
4. 10 - 2 = 8  ?

It then reviews some rules, stating that the “equals sign (=) tells you that the value on the left has to be the same value as on the right.”

Reading the first equation, the video notes that 6 is 6 and that both the values are the same on either side, meaning equation one is true.

The video goes through the rest of the problems, noting that your students either have to add or subject the values on the left and see if they are the same as the value on the right.

In order to help your students add or subtract, you can use a number line like the video does. This helps visualize the adding and subtracting process for students. The video demonstrates two ways to subtract on a number line as well.

At the end of the video, all the equations are marked as true or false.

1. 6 = 6         ✓
2. 5 + 2 = 7   ✓
3. 10 - 4 = 7  X
4. 10 - 2 = 8  ✓

Video 2: Practice with Addition and Subtraction Signs

The video begins by reviewing what equations are. Boddle gives three examples of equations and discusses why each equation functions. The video states that equations have an equal sign, and each side of the equation must be the same value.

1. 4 + 0 = 4
a. This is an equation because the value on the left (4 + 0) is the same as the value on the right (4).
1. 1 + 5 = 6
a. This is an equation  because the value on the left (1 + 5), when solved, is the same as the value on the right (6).
1. 2 + 3 = 4 + 1
a. This is an equation because 2 + 3 is equal to 5 and 4 + 1 is equal to 5; therefore both sides have the same value.

The second half of the video provides additional practice for your students so they can better understand equations. Boddle provides some equations with the addition and subtraction symbols missing. Your students can fill in the blanks and make the statements true.

The video reminds students that both sides must be the same value in order to be a true equation.

1. 5 _ 4 = 9
a. Boddle first tries the plus sign. When 5 and 4 are added, they equal 9.
b. Both sides of the equation are the same.
c. The answer is plus (+).
1. 3_ 1 = 2
a. Boddle first tries the plus sign. When 3 and 1 are added, they equal 4.
b. 4 is not the same as 2; therefore, the answer is not plus.
c. Boddle then tries the minus sign. When 1 is subtracted from 3, they equal 2.
d. Both sides of the equation are the same.
e. The answer is minus (-).

Want more practice?