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# 3.1 Basic Arithmetic Expressions

## Arithmetic Operators

Arithmetic operators are used to conduct mathematical operations in your code. The chart below contains the different types of arithmetic operators you can use in C:

The first one, “ + ”, is the addition operator, which allows you to add numbers together. You can use it with regular numbers, and with variables too.

Examples:
``int num = 21 + 46;``

``````int num1 = 21;
int num2 = 46;
int num3 = num1 + num2;``````

### Subtraction

The second operator, “ - ”, is the subtraction operator, which allows you to subtract a number from another. Like the addition operator, you can use it with regular numbers, and with variables too.

### Multiplication

The third operator, “ * ”, is the multiplication operator, which allows you to multiply numbers together. Like the operators we have discussed already, you can use it with regular numbers and with variables too.

### Division

The fourth operator, “ / ”, is the division operator, which allows you to divide a number by another. Like the first three operators, you can use it with regular numbers and with variables too.

### Modulus

The last arithmetic operator on this chart, “%”, is the modulus operator. Chances are you haven’t seen this one before, so let’s clarify what this one does. When you divide a number by another number, you are not always going to have them divide into each other perfectly. Sometimes, you end up with a remainder. The modulus operator allows you to store the remainder of two numbers or variables in another variable. This one might seem a little tricky at first, so here are some examples:

## Practice

### Arithmetic

Create a num variable and create a mini calculator by using every arithmetic operator on it.
Solution Code
``````#include <stdio.h>

int main(void) {
int num = 3;
num = 3+1;
num = 3-1;
num = 3*1;
num = 3/1;
}``````

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