To convert a number to binary:

$1.$ Stop if the number is zero

$2.$ Use the remainder operator $(\%)$ to divide by two and check the remainder

a$.$ If the remainder is $1,$ push a $1$

b$.$ If the remainder is $0,$ push a $0$

$3.$ Set the number to itself divided by two

$4.$ Go to step $1$

$5.$ When done converting, use the stack and a StringBuffer to convert the stack contents to a string

$6.$ Return that string