```
In [10]:
```a=45
print(a)

```
```

```
In [11]:
```b=25
print(b)

```
```

Okay, neat. Can I only make variables that hold numbers?

```
In [12]:
```x="Hello Everybody!"
print(x)

```
```

```
In [13]:
```Amiright=True
print(Amiright)

```
```

Wait a minute, the numerical variables above are only integers...can we use decimal points?

```
In [14]:
```fl = 0.54
print(fl)

```
```

Wow look at all those variables! What do I call them all?

```
Terminology
Integer:Any whole number:42,2635
Float:Any number at all
String:Anything with letters in it
Boolean:Any True or False statement
```

These will become useful when you get an error and you are wondering what it means.

```
In [15]:
```print(a)
print(b)
c=a+b
print(c)

```
```

Note that our a and b didn't go away. Variables will stick around until you change them.

```
In [16]:
```c=a/b
print(c)
c=c+a
print(c)

```
```

```
In [28]:
```#addition
print(2+2)
#division or quotient
print(42/42)
#multiplication
print(2*3)
#subtraction
print(2-8)
#exponent or power
print(2**3)
#modulo or remainder
print(10%7)
#additive equality
a=56
a+=10
print(a)
#greater than
print(10>5)
#less than
print(10<5)
#is equal to
print(11==10)
#is not equal to
print(10!=10)
#and
print(11==11 and 12>10)
#or
print(10==11 or 5<7)

```
```

Let's explore how a computer thinks about strings. Beginning with some natural ideas.

- Does the computer know how long a string is?
- What if you want only part of a string?
- What does it mean to add two strings?
- How does a computer "see" the string?

```
In [20]:
```string="hiya"
print(len(string))

```
```

```
In [21]:
```print(string[0])

```
```

```
In [25]:
```string1=" there!"
print(string+string1)

```
```

```
In [26]:
```print(string-string1)

```
```

The computer sees the string as a list of individual letters. In the next section, we will discuss lists in a more general sense. In the previous example, we had two strings, "heya", and " there!". The computer sees "heya" as

$$\left["h", "e", "y", "a"\right]$$```
In [ ]:
```