# Numbers

``age = 12print(age)``

Note that there are no quotes sourrounding the variable value (the number).

## Arithmetic​

Arithmetic is exactly the same as we write it.

Except multiplication and division are written as `*` and `/` respectively.

``age = 12print(age + 1)print(age - 1)print(age * 2)print(age / 2)``

## The difference between `'13'` and `13`​

These values are different.

Though they both represent numbers to humans, it is not the same for computers.

Computers think all `'13'` are strings and treat them as such.

So, number methods will not work on `'13'` nor will string methods work on `13`.

Simply, put a `'13'` in quotes to make it a string.

``age = '13'print(age + '1')``

The code above will print `131` because the string is treated as a string.

The code above will print the types of the variables.

``age = '13'print(type(age))age = 13print(type(age))``

## Changing to numbers​

Note that `input()` returns a string.

``a = input("")b = input("")print(a + b)``

The values are not added, but concated together.

``a = input("")b = input("")print(int(a) + int(b))``