Rounding is a pretty important skill in Python. In this article, I will show you** **how to** **round a number to the nearest 100 in Python**.** I would use ways like customizing a function using Python’s built-in functions and using two functions, round up and round down, in the math module.

**Round a number to the nearest 100 in Python**

**Customize a function that returns the nearest 100 divisible values**

I will customize a divisible function by the nearest 100 using the round() function.

**Syntax:**

`round(number[, ndigits])`

**Parameters:**

**number:**Number you want to round.**ndigits:**The number of digits you want after the decimal point.

**Return value from the round() function:**

- If there are no ndigits, the function returns the nearest integer.
- If two arguments are provided, the function returns a number with ndigits decimal places after the decimal point.

**Example:**

# Use the round() function to round def myRound(x): return round(x / 100) * 100 print("The nearest rounded number is divisible by 100:", myRound(255)) print("The nearest rounded number is divisible by 100:", myRound(311)) print("The nearest rounded number is divisible by 100:", myRound(51))

**Output:**

```
The nearest rounded number is divisible by 100: 200
The nearest rounded number is divisible by 100: 300
The nearest rounded number is divisible by 100: 100
```

In the above example, I instantiate a function that I named ‘myRound’ that returns the nearest divisible by 100 as follows: I use integer division (the / operator) as the round() parameter, and round() I don’t take any extra digits after the decimal point, so I always get an integer as a result. Multiply that result by 100 to get the nearest number that is divisible by 100.

The second way to use the round() function to round a number to the nearest 100 is setting the ndigits parameter to -2, which has the effect of rounding to the nearest multiple of 100.

**Example:**

def myRound(value): return round(value, -2) print("The nearest rounded number is divisible by 100:", myRound(243)) print("The nearest rounded number is divisible by 100:", myRound(311)) print("The nearest rounded number is divisible by 100:", myRound(134))

**Output:**

```
The nearest rounded number is divisible by 100: 200
The nearest rounded number is divisible by 100: 300
The nearest rounded number is divisible by 100: 100
```

**Use the math.ceil() and math.floor() functions**

**Syntax**:

`math.ceil( x )`

**Parameters:**

**x:**A numeric expression.

The ceil() function returns the smallest integer that is not less than x.

**Example:**

- Import math module to call ceil() function.
- The ceil() function rounds the value from the function’s integer division. The result returned is an integer not less than the value of the division.
- Multiply that result by 100 to get the nearest number that is divisible by 100.

import math # Use the math.ceil() to round up nearest 100 def myRound(number, n = 100): return math.ceil(number / 100) * 100 print("Number rounded up to the nearest divisible by 100:", myRound(243)) print("Number rounded up to the nearest divisible by 100:", myRound(311)) print("Number rounded up to the nearest divisible by 100:", myRound(134))

**Output:**

```
Number rounded up to the nearest divisible by 100: 300
Number rounded up to the nearest divisible by 100: 400
Number rounded up to the nearest divisible by 100: 200
```

To round down some of the best way using the math.floor() function.

**Syntax**:

`math.floor(`

*x*)

**Parameters:**

**x:**The number you need to round down.

The math.floor() function will round down a number to the nearest integer.

**Example**:

import math # Use the math.ceil() to round down nearest 100 def myRound(number, n = 100): return math.floor(number / 100) * 100 print('Number rounded up to the nearest divisible by 100:', myRound(243)) print('Number rounded up to the nearest divisible by 100:', myRound(311)) print('Number rounded up to the nearest divisible by 100:', myRound(134))

**Output**:

```
Number rounded down to the nearest divisible by 100: 200
Number rounded down to the nearest divisible by 100: 300
Number rounded đown to the nearest divisible by 100: 100
```

**Summary**

So the article is over. I hope you understand how to round a number to the nearest 100 in Python. You can use the round() function and set the 2nd parameter to – 2 for short. Thank you for taking the time to read this article.

**Maybe you are interested**:

- Round a float to the nearest 0.5 in Python
- Round a number to the nearest 1000 in Python
- Round a number to the nearest 5 in Python

My name is Jason Wilson, you can call me Jason. My major is information technology, and I am proficient in C++, Python, and Java. I hope my writings are useful to you while you study programming languages.

**Name of the university: **HHAU

**Major**: IT

**Programming Languages**: C++, Python, Java