# Mathematics with Python and Ruby/Whole numbers in Python

Whole numbers are not the only numbers, as we will see in the following chapters. So what does *Python* do to know if a number is whole? As the language is weakly typed, it must guess. The criterium is simple: in order for a number to be whole, it must not have a decimal point.

# Whole numbers in Python[edit]

Thus, if one enters

```
a = 3
print(type(a))
b = 3.14
print(type(b))
c = int(b)
print(c)
```

one notes that *Python* knows that *a* is whole, that *b* is not, and that *c* can be whole although it was obtained from *b* (which is real).

Certain calculations that should give a whole result do not always do so in *Python*. For example, while , *Python* treats this number as a real number (not a whole number)!

```
from math import sqrt
a = sqrt(100)
print(a.is_integer())
```

# Operations[edit]

## Addition, subtraction and multiplication[edit]

The first three operations are denoted by the symbols *+*, *-* and *** as in most programming languages. The sum, difference and product of two (or more) whole numbers are all integers.

```
a=5
b=-8
print(a+b)
print(a-b)
print(a*b)
```