# Math and Logic

### Basic arithmetic

You can use the Ruby shell (IRB) as a calculator. Ruby uses the standard arithmetic operators:

``````1 + 1  #=> 2
10 * 2 #=> 20
35 / 5 #=> 7
10.0 / 4.0 #=> 2.5
``````

The modulus operator returns the remainder from division:

``````4 % 3 #=> 1
``````

`**` is the exponent operator:

``````2 ** 5   #=> 32
``````

### Equality and Comparisons

Ruby lets you use standard syntax or english for equalities and logical operators.

``````#check equality
1 == 1 #=> true

# Inequality
2 != 1 #=> true

# not
! true  #=> false
not true  #=> false
``````

### Logical Operators

And and Or

``````true && true #=> true
false || true #=> true
``````

you can also use words:

``````true and false #=> false
true or false #=> true
``````

Everything in ruby is considered `true` except for `false` and `nil`:

``````!nil   #=> true
!false #=> true
!1     #=> false
!0     #=> false
``````

An or statement will return the first true value it encounters:

``````nil || 7          #=> 7
nil || false || 8 #=> 8
1 || 2            #=> 1
``````

You will be given two numbers `a` and `b` as input. a is considered great if a2 is greater than 4 * b and a is greater than b. Return `true` if a is great and `false` otherwise.