#!/usr/bin/env bash
function one(){
# Print the result to stdout
echo "$1"
}
function two() {
local one=$1
local two=$2
# Do arithmetic and assign the result to
# a variable named result
result=$((one + two))
# Pass the result of the arithmetic to
# the function "one" above and catch it
# in the variable $1
one "$result"
}
# Call the function "two"
two 1 3
Try that argument passing this way: