# Add, Subtract, Multiply, or Divide a Range of Numbers

### What is a Whole Number

Whole numbers are numbers that are not fractions or decimals. They are also called integers, counting numbers, natural numbers, etc.

### What is an Integer?

An integer is a number that has no fractional component. An integer can be positive, negative, or zero.

The set of integers comprises the natural numbers including 0; the whole numbers including 0; the positive numbers including 0; and also 1.

### Addition and Subtraction of Whole Numbers

Addition and subtraction are two operations that are fundamental to mathematics.

Addition is when you put together two numbers of the same kind - in this case, integers. So when you want to add 2 + 3, the answer is 5 because you are adding two integers together. Subtraction is when you take away one number from another number of the same kind - in this case, integers. So for example, when you want to subtract 3 from 5, the answer is 2 because 5-3=2 in integer terms.

### Multiplication and Division of Whole Numbers with Integers

When we want to find the product or quotient of two whole numbers and they are both integers, we can use a simple multiplication or division.

For example, to find the product of 5 and 4, we can multiply 5 with 4 which is 20. In order to divide 4 by 2, we can divide 4 by 2 which is 2.

### What are the Basic Arithmetic Operations?

Arithmetic operations are calculated using the standard order of operations:

You may also know these as PEMDAS (parentheses, exponents, multiplication and division, addition and subtraction).

This order is applied to the numbers involved in the calculation.

### Addition & Subtraction without a Calculator

Being able to quickly calculate math problems is a vital skill for every person. Whether you are in school, work, or home, everyone needs to know how to do math. The good news is that there are some easy ways to calculate these problems without the need for a calculator.

There are many different ways that you can use to subtract without a calculator. Using mental math is one of the easiest ways because it doesn't require any equipment at all. There are also other techniques that can be used such as using objects in your surroundings or using parts of your body as tools for subtraction.

### Multiplication & Division without a Calculator

Some of us might not know this but there are many ways to do multiplication and division without a calculator. The two most common types of multiplication and division without a calculator are:

- The long way: This is when we manually do the math by just multiplying the numbers together. Here, we typically use a paper and pen (or pencil).

- Mental math: This is when we use our brain or memory to calculate the answer to an equation.