Sum

In mathematics, the sum is the result of adding two or more numbers or quantities together. It is a fundamental operation in arithmetic and is denoted by the plus sign (+).

Example:

If we have the numbers 3, 5, and 7, the sum of these numbers is found by adding them together: 3 + 5 + 7 = 15.

Properties of Addition:

1. Commutative Property: The order in which numbers are added does not change the sum. In other words, a + b = b + a.
2. Associative Property: The way in which numbers are grouped does not change the sum. In other words, (a + b) + c = a + (b + c).
3. Identity Property: The sum of any number and zero is the number itself. In other words, a + 0 = a.

Study Guide:

To calculate the sum of two or more numbers:

1. Write down the numbers to be added, one below the other.
2. Align the numbers by place value (ones with ones, tens with tens, etc.).
3. Start adding from the rightmost column (the ones column) and carry over any excess to the next column if necessary.
4. Continue adding the columns to obtain the final sum.

Remember to apply the properties of addition to simplify calculations and understand the relationship between numbers in a sum.