## Addition Concepts

Addition, one of the four basic operations that form the foundation of arithmetic, is an essential part of the computation work of the elementary school grades. Children will often be able to solve simple addition problems using strategies they learned in kindergarten, such as drawing a picture, using counters, or counting on to find a sum.

Children are encouraged to use various manipulatives as they add two numbers. The general form of an addition sentence is written as a + b = c, where a, b, and c are whole numbers. Letters such as a, b, and c are called variables. A variable is a quantity that represents a number. At this grade level, blanks or boxes are used rather than variables. Children learn that the plus sign (+) indicates addition, that the answer to an addition problem is called the sum, and the numbers being added are called addends, but this vocabulary is not necessary for children to remember at this time. The equals sign indicates that one quantity has the same value as another. Thus, 3 + 2 = 5 indicates that 3 + 2 is equal in value to 5, or that 3 + 2 is another way to name 5.

Finally, children are introduced to the vertical form of writing addition facts as a readiness activity for future additions involving multi-digit numbers. In general, a + b = c, where a, b, and c are whole numbers, can also be written as

a | |

+ | b |

c |

**Teaching Model 2.3:** Use Symbols to Add