An addition sentence is a number sentence used to express addition. It is just one of many ways that the concept of addition can be taught. More generally, an addition sentence is a type of equation that specifically involves the operation of addition. It is made up of at least two addends (the terms of the equation along with the sum), a plus sign, an equality symbol (=), and a sum (or total), as shown in the figure below.

Practicing addition using addition sentences can help a person get more comfortable with how the various components of an equation are written. Equations are used throughout all areas of mathematics, so gaining a basic understanding of them early on can be helpful. A person who is comfortable with addition sentences and the concept of equations will have a good foundation for learning other operations, and eventually, more complex topics such as algebra.

Addition sentences are just one of many ways to learn or practice addition. Others include grouping real life objects, performing mental math, using addition tables, and more. One way to use addition sentences is to use practice worksheets that involve determining the missing terms in an addition sentence. When first starting it can be helpful to see an addition fact written in its entirety, but having to fill in the missing terms in an addition sentence can help with recognizing or memorizing the various addition facts.

1. 1 + 7 + 4 = ?:

1 + 7 + 4 = 7 + 5 = 12

2. 4 + 1 + 7 = ?:

4 + 1 + 7 = 8 + 4 = 12

The addition sentences above exhibit both the associative and commutative properties of addition. In this manner, on top of providing practice completing addition problems, it is also possible to use addition sentences to demonstrate various properties of addition.

Also, the missing term does not always need to be the sum; it can be one of the addends. To make the addition sentences yet more complicated, there can also be more than one missing term. This provides even more practice and exposure to various addition facts, since it makes it possible to achieve the same sum using different addends.

1. 1 + ? + 4 = 17:

1 + ? + 4 = 5 + ? = 17

5 + 12 = 17

2. 4 + 1 + 7 = ?:

? + 1 + ? = 17

This addition sentence has multiple solutions. Some of them include:

1 + 1 + 15 = 17

9 + 1 + 7 = 17

8 + 1 + 8 = 17