Numbers can be combined using the four basic
arithmetic operations `+`

`-`

`*`

`/`

and
parentheses `( )`

Traditional order of operations applies,
with `*`

and `/`

being done before `+`

and `-`

.
Of course, by using parentheses, you can
force any order you like.

write 4 * 4 + 3 * 3 write 4 * (4 + 3) * 3

You can also negate a value by putting a `-`

before it. (Or leave a value's sign unchanged
by putting a `+`

before it.)

To avoid confusion, a `-`

or
`+`

that is used for negation should
have a space to its left but not to
its right, and a `-`

or `+`

that is
used for subtraction or addition should
have spaces on both sides:

x = -5 write x - sqrt -x

The `**`

operator can be used for powers;
`x ** y`

is `x`

raised to the `y`

power:

write 2 ** 3

Powers also be written using `pow`

:

write pow(2, 3)

There are many other math functions.
They include `sqrt`

,
`abs`

, `round`

, `ln`

,
`max`

, and `sin`

.