The methods of using basic mathematical operations in PHP are as follows: 1. Addition numbers are used to support integers and floating-point numbers, which can also be used for variables. String numbers are automatically converted but are not recommended to dependencies; 2. Subtraction numbers are used to - signs, variables are the same, and type conversion is also applicable; 3. Multiplication numbers are used to * signs, which are suitable for numbers and similar strings; 4. Division numbers are used to avoid dividing by zero, and note that the result may be floating-point numbers; 5. Taking the modulus numbers are used to judge odd and even numbers, and when processing negative numbers, the remainder symbol is consistent with the dividend. The key to using these operators correctly is to ensure that the data types are clear and the boundary situation is handled well.

Sure, here's how you actually use basic math in PHP. It's straightforward, but there are a few things worth pointing out.

Adding numbers with

Use the plus sign to add two numbers. This works for both integers and floats.

 echo 5 3; // Outputs: 8

You can also add variables:

 $a = 10;
$b = 5;
echo $a $b; // Outputs: 15

Just keep in mind that if one of the values ??is a string that looks like a number (like "12" ), PHP will usually convert it automatically. But relying on that can be risky — better to make sure your values ??are numeric before doing math.

Subtracting with -

Same idea as addition, just use the minus sign:

 echo 10 - 4; // Outputs: 6

Variables work the same way:

 $x = 20;
$y = 7;
echo $x - $y; // Outputs: 13

Again, type juggling apply here too. If you subtract something that isn't a number, you might get unexpected results or warnings.

Multiplication with *

Multiply using the asterisk symbol:

 echo 6 * 3; // Outputs: 18

With variables:

 $val1 = 8;
$val2 = 4;
echo $val1 * $val2; // Outputs: 32

This one's pretty safe — as long as both values ??are numbers (or number-like strings), it should work fine.

Division with /

Divide using the forward slash:

 echo 20 / 4; // Outputs: 5

What if you divide by zero? That triggers a warning. So always make sure the denominator isn't zero:

 $numerator = 10;
$denominator = 0;

if ($denominator != 0) {
    echo $numerator / $denominator;
} else {
    echo "Can't divide by zero!";
}

Also note that dividing integers doesn't always give an integer result:

 echo 5 / 2; // Outputs: 2.5

If you want only the integer part, cast it or use intval() .

Modulo with %

The percent sign gives you the remainder after division:

 echo 10 % 3; // Outputs: 1

It's useful for checking even/odd numbers:

• Even: $number % 2 == 0
• Odd: $number % 2 == 1

But watch out — module works with negative numbers too, and the sign of the result matches the dividend:

 echo -10 % 3; // Outputs: -1
echo 10 % -3; // Outputs: 1

So behavior can vary depending on what you're expecting.

That's all the basic operators. They do exactly what you'd expect most of the time, but don't ignore edge cases like dividing by zero or mixing types. Keep your data clean and check your inputs, and you'll avoid most issues.

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