addLargeNumbers$($number$1,$ number$2)$

read the numerals of the first number and store them on one stack

read the numerals of the second number and store them on another stack

var result :$=0$

while at least one stack is not empty

pop a numeral from each nonempty stack and add them to result

push the unit part of addition onto a new stack called the result stack

store the carry part of the addition in result

push result onto the result stack if it is not zero

pop numbers from the result stack and display them