states that the sum of 3 and 4 is equal to the sum of 4 and 3. The sum of two numbers is unique, meaning that there is only one correct answer for the sum of any given pair of numbers. Addition has an inverse operation, called subtraction, which can be used to find the difference between two numbers. For example, the difference between 7 and 3 is 4, because 7 minus 3 equals 4. Addition is used in a variety of contexts, including comparing quantities, joining quantities, measuring, and separating. In addition, it can be represented using the symbol "+" and follows the commutative property, meaning that the order of the addends does not affect the sum. When the sum of a pair of digits results in a two-digit number, the tens digit is referred to as the "carry digit" in the addition algorithm. In elementary arithmetic, students typically learn to add whole numbers and decimals, and may also learn about more advanced topics such as negative numbers and fractions. Example Using the numbers 653 and 274, starting with the ones column, we find that the sum of three and four is seven. Next, the tens column. The sum of 5 and 7 is 12, which has two digits. The last digit of 12 is written under the tens column, while the first digit is written above the hundreds-column as a carry digit. Next, the hundreds-column. The sum of 6 and 2 is 8, but the carry digit is present, which added to 8 equals 9. There are no other digits to add, so the algorithm is finished, yielding the following equation as a result: Subtraction Subtraction is the process of finding the difference between two numbers, where the minuend is the number being subtracted from, and the subtrahend is the number being subtracted. It is represented symbolically by the minus sign (-). For example, the statement "five minus three equals two" can be written as 5 - 3 = 2. Subtraction is not commutative, meaning the order of the numbers in the operation can change the result. For example, 3 - 5 is not the same as 5 - 3. In elementary arithmetic, the minuend is always larger than the subtrahend to produce a positive result. However, if the minuend is smaller than the subtrahend, the result will be negative. In addition to finding the difference between two