add To combine two or more numbers into one equivalent number (called sum), represented by the symbol +. Example: 2 + 1 = 3

Procedure/Formula Demonstration: 1-digit + 1-digit without regrouping 1-digit + 1-digit with regrouping Sum of three 1-digit numbers without regrouping Sum of three 1-digit numbers with regrouping Sum of four 1-digit numbers with regrouping 2-digit + 1-digit without regrouping 2-digit + 1-digit with regrouping 2-digit + 2-digit without regrouping 2-digit + 2-digit with regrouping Sum of three 2-digit numbers without regrouping 3-digit + 1-digit without regrouping 3-digit + 1-digit with regrouping 3-digit + 2-digit without regrouping 3-digit + 2-digit with regrouping 3-digit + 3-digit without regrouping 3-digit + 3-digit with regrouping Sum of three 3-digit numbers without regrouping Sum of four numbers with regrouping Sum of five numbers with regrouping Related Term: subtract