x and elem are both integers, so x * elem is also an integer. You’ve assigned the result to a variable called new_list, but it’s not a list. Each time through the loop, the previously assigned value is discarded. When you exit the loop, only the final multiplication remains.
(And you mention the output is , but it is instead 3, so an integer, not a list)
You don’t assign to the .append method, you call it with an argument. So this should be instead: